Scarlet lily leaf beetle (Lilioceris lilii) earns its name by devouring lilies of every shape and size. Native to Europe, this pest made its way to Canada in 1945 and reached the U.S. in 1992. While they may not yet be in your neighborhood, they might. So it’s a good idea to know what they look like and how to control them - just in case.

Lily leaf beetle description

The bright reddish-orange wing cover of lily leaf beetles makes them easy to spot. Black legs, head, and antennae stand out in clear contrast against green leaves. Adults average 1/2” long.

Eggs are irregularly shaped and laid in rows. At first they are tan colored. Just before they hatch, they turn bright red. Larvae look like tiny brown, orange, yellow, or even greenish slugs with black heads.

Lily leaf beetle lifecycle

Eggs are laid on host plants, usually on the underside of leaves. After hatching, larvae feed for 2 - 3 weeks before dropping to the ground to pupate in the soil. Adults overwinter in sheltered areas that may not necessarily be near host plants. In spring, they emerge and mate. Each female might lay 250-450 eggs.

Damage caused by lily leaf beetles

Both adults and larvae feed on buds and leaves. Very often, nothing is left but stems. Lily leaf beetle larvae have a nasty habit of collecting their own excrement on their backs. This is believed to be a defense mechanism. I’ll bet it works, too!

Lily leaf beetle control

Hand-picking is the best control method. Severe infestations may warrant neem oil or spinosad application.

All parts of the kohlrabi plant are edible. Sweeter and more mild than either cabbage or turnips, kohlrabi (Brassica oleracea) is a highly nutritious vegetable, with plenty of fiber and vitamins.

Kohlrabi description

The swollen bulb-shaped portion of kohlrabi is actually a modified stem. The outer skin can be pale green or purple, depending on the cultivar. The blue-green leaves look striking. This biennial plant makes an attractive addition to your garden, as well as your dinner table. ​

How to grow kohlrabi

Kohlrabi is generally a cool season crop. It needs full sun and good drainage. Kohlrabi plants prefer a soil pH of 5.5 to 6.8. If your soil is more alkaline than that, acidification may be a good idea.

Here in San Jose, California, kohlrabi plants can be started in February and March, and then again in September and October. These are heavy feeders, so top dressing with aged compost can ensure they have access to all the nutrients they need. Mulching around plants is also helpful. Regular irrigation will prevent your kohlrabi from becoming woody textured.

If you are starting with seedlings, put them in the ground so that the first set of leaves is just above the soil line. If growing seeds, cover seeds with 1/4” of soil and space plants 9-12” apart. It takes 45 to 60 days for kohlrabi to reach maturity.

Kohlrabi pests and diseases

Cabbage loopers, cutworms, and imported cabbageworms are the most common pests of kohlrabi. These plants are susceptible to cabbage yellows, clubroot, and downy mildews.

Give kohlrabi a try and see how productive these plants can be!

There is debate over how they got their name, being neither crickets nor from Jerusalem. Whatever you call them, Jerusalem crickets give me the creeps (unlike most insects), even though they are mostly beneficial.

You will generally only see them in the evening or after a heavy rain. Leaving the sprinklers on too long can also coax them out of hiding.

Jerusalem cricket description

Native the the western United States and Mexico, there are several different species of Jerusalem cricket. Most of them appear waxy, with brown and yellow bands. These nocturnal flightless insects are large. They average 2” long with a big head. While they cannot sting, Jerusalem crickets can inflict a painful bite, as well as discharge a nasty smell, but only if provoked. ​

For the most part, these benign opportunists pose no threat to your garden. Instead, they are more likely to feed on insect pests and help process dead plant material into nutrients that your growing plants can use.

They still give me the creeps.

One question that comes up when gardening is whether you should use organic fertilizer or  inorganic fertilizer.

Whatever their source, certain nutrients are needed for plants to grow and thrive. In many cases, those nutrients are present in the soil. Some times they are not. Without a soil test, you simply cannot know for sure. If a soil test shows there are nutrient deficiencies, you will need to add fertilizer. Should you use organic or inorganic fertilizer?

Inorganic chemicals

“Better living through chemistry” has been the victory cry against countless diseases, inconveniences, and poor crop yields. There is no denying that the introduction of chemical fertilizers, pesticides, herbicides, and insecticides was a boon to farmers around the world. Of course, we now recognize that everything comes at a price and that it is important to weigh the pros and cons of every situation.

The downside of chemical pest killers is that the pests evolve faster than we do and the point is reached, sooner or later, where the pests can handle the poisons but we can't. Inorganic fertilizers, however, are a different story.

One advantage of inorganic gardening is that you know exactly which nutrients are present and at what concentration. The same cannot be said for composted chicken bedding. Also, inorganic fertilizer is generally in a form easiest to use by plants. 

There are also synthetic fertilizers, such as ammonium sulfate, that start out as naturally occurring minerals, which are then processed. These modified minerals are considered acceptable for use in organic gardens.

Organic nutrients

Organic fertilizers come from manure, compost, bone meal, feather meal, and blood meal. Each of these amendments comes from a plant or animal source. Surprisingly, many of these nutrients must be acted upon by microorganisms to convert them into inorganic forms that plants can use. If it is too hot or too cold for microbes to be active, that organic fertilizer may not be as helpful as we might wish.

That being said, organic fertilizers tend to contain a wider variety of nutrients and microorganisms, which may or may not be advantageous for our plants. Believe it or not, there is still a lot we don’t know about plants.

A rose is a rose

As far as your plants are concerned, it doesn’t matter. To a plant, a molecule of nitrogen looks the same, whether it came from a factory or buffalo urine. It really doesn’t matter. The same is true of all plant nutrients. To a plant, the source of the molecule is meaningless. So why do we care one way or the other?

In both cases, too much fertilizer can burn plants, excessive application can lead to run-off and pollution, and their proper use can improve plant health and production. For me, I lean toward the organic side of the fence simply because it makes me feel good. I like the idea of it. Even though I know that, at the molecular level, it doesn’t really matter.

Did you know that the real difference between organic and inorganic is simply the presence (or lack thereof) of a carbon molecule? Nearly all inorganic compounds lack carbon.

Now you know.

Dichotomous 

Dichotomous venation is seen as repeated forking or Y-branching, as seen in Ginkgo biloba leaves.

Other venation patterns

You may also run into a few other leaf vein arrangements that don’t conveniently fall into one of those four groups. For example:

• If two or more secondary veins arch halfway to nearly all the way to the tip, it is called acrodromous.
• If the primary vein splits into more primary veins, it is called palinactodromous.

When you are trying to identify an unknown plant, venation can help solve the mystery!

Fern reproduction

Ferns are unique in their method of reproduction and they are the only plants with two distinct living stages. As each spore matures, it becomes a sporophyte. Sporophytes that land in hospitable environments grow into very tiny, short-lived plants called gametophytes. Gametophytes have two sets of reproductive organs: a female archegonia and a male antheridia. Fertilization can take place within the same plant or between two neighboring plants. This fertilization produces a new sporophyte that grows into an adult fern.

Edible ferns

While most ferns are not considered edible, they also tend to not be poisonous. There are some varieties of fern that are edible, such as:

• bracken (Pteridium aquilinum)
• cinnamon fern (Osmundastrum cinnamomeum)
• king fern (Ptisana salicina)
• licorice fern (Polypodium glycyrrhiza)
• ostrich fern (Matteuccia struthiopteris)
• royal fern (Osmunda regalis)
• vegetable fern (Diplazium esculentum)

As always, do not eat anything you are not sure to be safe.

Fern pests and diseases

Ferns are naturally resistant to most plant-eating insects. One edible fern in particular, Tectaria macrodonta, has a gene that was transferred to cotton plants, providing resistance against whiteflies! Foliar nematodes (Aphelenchoides fragariae) and soil borne nematodes (Pratylenchus) can sometimes be a problem.

Ferns are susceptible to diseases such as bacterial blight (Pseudomonas cichorii or P. gladioli), Pythium root rot, and Rhizoctonia blight. Infected plants should be discarded. Environmental problems, such as drought, which causes graying, and over-fertilization, which results in frond lobing and leaf tip burn, can be avoided with good cultural practices. This means investing in disease-free plants, using only as much fertilizer as recommended for each fern species, and avoiding overhead watering. 

If you have a moist, shady crevice in your garden, ferns might be just what you've been looking for!

The fungi responsible for take all disease, Gaeumannomyces graminis, is found in the soil. It enters young plant roots and can often be seen as dying patches in a lawn or field.

Take all disease symptoms

The fungus enters the xylem and blocks the flow of water, causing stunting, yellowing, and reduced tillering. Tillering refers to the way lateral shoots emerge from the base of the stem, a common growth style of cereals. Infected plants mature faster than normal and have bleached seed heads and blackened roots and crowns.

Preventing take all disease

There are no effective chemical treatments against take all disease available to gardeners. There is a seed treatment that shows promise, so be sure to get certified disease-free seeds from reputable suppliers. Excessive liming and nutrient imbalances exacerbate this disease. If take all disease appears in your lawn, there isn’t much you can do besides improving drainage. If it appears in your barley, corn, millet, rice, sorghum, triticale, or wheat, the best thing you can do is rotate crops. Oats and rye, while cereal grains, are not susceptible to take all disease. 

Take all disease can build up in the soil, particularly in monoculture crops that are grown in the same place year after year. ​

There is one soil amoeba that feeds on the take all disease fungi. This unique protozoa is a type of vampyrellid. Vampyrellids are affectionately known as soil vampires because of the way they leave puncture marks in their victims.

Streaked avocado skins may indicate a disease known as sunblotch.
 
Sunblotch identification

Unlike sunburn damage, which bleaches leaves, sunblotch appears as yellowish, reddish, or white streaks on the stems and skin of avocado fruits. Common symptoms of sunblotch include stunting, distorted leaves and petioles, and reduced fruit production. Rectangular cracking in the bark of older branches may also occur. Unfortunately, this disease can go unnoticed for years before symptoms become visible. By then, several nearby trees have probably become infected.

Cause of sunblotch

Until recently, botanists thought sunblotch was a genetic disease. Now we know it is a viroid infection. Viroids are the smallest known infectious pathogens, and they only attack plants. Unlike viruses, which contain DNA and RNA, viroids only contain RNA. This particular viroid attacks many tropical and subtropical plants, including avocados.

Sunblotch control

Trees infected with sunblotch must be removed and destroyed. Tree removal is expensive and potentially dangerous, so prevention is the only option.

Sunblotch spreads through infected pollen, seeds and budwood. You can’t do anything about infected pollen if the source is on someone else’s property (besides educating your neighbor). But you can invest in disease-free bare-root trees. You can also ensure that any grafting projects you take on involve only healthy trees. And be sure to sanitize your garden tools after working on potentially infected trees with a household cleaner.

European fruit lecanium scale might be a long name, but these garden pests can make short work of your pomegranates, citrus, and olives.

European fruit lecanium scale description

European fruit lecanium scale is a soft scale insect. This means the shiny brown convex cover is not as hard as armored scale covers. You can identify European fruit lecanium scales because the brown cover has several ridges on it, while other soft scale insects do not. 

European fruit lecanium scale lifecycle

European fruit lecanium scale larvae are normally found on twigs and small branches. As temperatures begin to rise in spring, they develop the telltale dome-shaped cover. Adult females fill the space under their cover with eggs and then they die. When the eggs hatch, the nymphs, or crawlers, come out from underneath the scale covers and hide out on the underside of leaves. By late July or August, these pests migrate to fruit. There can be two generations each year and most of the insects present will be in the same life stage.

Damage caused by European fruit lecanium scale

When European fruit lecanium scale larvae feed, they attach themselves to the outside of twigs and fruit and pierce the surface. This causes cosmetic damage as well as providing points of entry for other pests and diseases. Also, European fruit lecanium scale feeding results in the excretion of honeydew (sugary bug poop), which sooty mold fungi find delightful. The only exception is that scale feeding on pomegranates does not result in honeydew deposits. Instead, tiny piles of sugar are seen. These sugar piles are easily brushed off of twigs and fruit.

European fruit lecanium scale controls

Natural enemies are the best controls for European fruit lecanium scale. Twicestabbed lady beetles, steel blue lady beetles, and lacewings will all help fight soft scales. You can also wrap tree trunks with sticky barriers to remove the protection (and disease-carrying potential) provided by ants. 

Finally, prune trees for good air flow and structure to keep trees healthy.

Adult cigarette beetles only live for a few weeks and do not eat. They can, however, fly. And cigarette beetle larvae are surprisingly destructive. 

Mottled, stunted cilantro plants may have apium virus Y disease.

Apium virus Y disease is carried by aphids. This viral disease is also found on celery, carrot, dill, and poison hemlock. It can infect parsley, as well, but no visible symptoms occur.

​Apium virus Y disease symptoms

Leaf mottling or mosaic patterns, stunting, cleared veins, and leaf distortions are all symptoms of apium virus Y disease. Older leaves may have yellow blotches, brown lesions, and yellow or brown line patterns. Younger leaves show only faint mottling. Lesions may form on petioles (leaf stems).

How to prevent apium virus Y disease
​
Since this disease is predominantly carried by aphids, you can help prevent this disease by controlling aphid populations (as much as is possible, of course). The virus can also be carried on clothing and tools, so be sure to sanitize your tools regularly and avoid walking through areas known to be infected. The virus does not remain vital for very long once it is inside an aphid. Creating physical barriers and increasing the distance between potential carriers can reduce the likelihood of this disease.

Crop rotation and the CAREFUL removal of poison hemlock can also help control this disease. There are no effective chemical treatments for apium virus Y disease.

Tree anatomy

Tree trunks are made up of several layers of tubes, surrounded by an outer layer of bark. These tubes are the vascular bundles that carry water and nutrients to the rest of the tree. One type of tube, called the xylem (or sapwood), pulls water and nutrients up from the roots. The majority of the trunk is made up of xylem cells. Another type of tube, called the phloem (or inner bark) carries the sugars made by the leaves through photosynthesis down into the rest of the tree. [I remember these two by saying, “Food flows down the phloem, while water and food rise in the xylem.”]

Just between the xylem and the phloem is the cambium layer. This is where the actual tree growth occurs. At the very center of the tree is the pith, surrounded by layers of xylem cells. As these xylem cells age, they eventually go through chemical changes that make them solid, losing their ability to transport water and nutrients. There is debate about whether or not these cells are still alive. This is the heartwood.

Characteristics of heartwood

Heartwood is very strong. The amount of heartwood present depends on the species. Some trees, such as ash, maple, and pine, have very thick heartwood. Other species have only a little heartwood. This group includes chestnut, mulberry and sassafras trees. Some tree species have no heartwood at all.

Heartwood gets larger over time. Young trees have very little heartwood, whereas older trees have significantly more. 

Heartwood is resistant to decay, but wood that looks like heartwood might also be infected with disease or dealing with an insect invasion. Louisiana homes built over 100 years ago out of of bald cypress heartwood appear to be as good as new because of the decay resistance of heartwood.

The next time you need to remove a large branch or tree trunk, take a closer look at the layers and see if heartwood is present.

The word pectin comes to us from the Greek word for “congealed” and with good reason. Pectin converts liquids into jelly, much the way gelatin does, the difference being that gelatin is made from animal skin and bones, and pectin is made from plants.

Pectin is found in most fruits, to one degree or another:

• apples 1-1.5%
• apricots 1%
• cherries 0.4%
• oranges 0.5-3.5%
• citrus peels 30%

But fruits are not the only plants that contain pectin. Carrots hold an average 1.4% pectin. Commercially, most pectin is made from citrus peels and apple pulp. Soft fruits, such as grapes and strawberries also contain pectin, but at very low levels.

How do plants use pectin?

Pectin is a structural chain of molecules used in cell walls. Pectin is a major component of cellulose, specifically a layer called the middle lamella. The middle lamella is an outer layer to plant cells that is used to bind cells together. This allows plants to grow larger. The level of pectin present in a plant varies over time due to factors such as plant age and seasonal changes.

As fruits ripen, the pectin begins to break down, which is why the fruit becomes softer. A similar process occurs during abscission, when parts such as leaves naturally die and fall from the plant. In some desert plants, pectin has been shown to help repair DNA by creating a mucous layer that captures dew.

How do we use pectin?

Pectin is used for more than jelly making. Pectin also provides dietary fiber and it acts as a thickening agent and stabilizer for desserts, cosmetics, and medicines. Pectin also binds to cholesterol and slows the rate at which we absorb glucose. This is especially true when the pectin is from apples and oranges. You know that old saying about an apple a day? I guess they were right!

The pectin found in apple pulp is also one of the best throat lozenges I know. The mucilaginous pectin provides a surprising amount of soothing relief. Next time your have a sore or scratchy throat, skip the menthol (an irritant) and slowly eat an apple.

Symptoms of molybdenum deficiency

Without molybdenum, leaves turn yellow and die and flowers may fail to form at all. The yellowing is often along leaf margins and downward cupping may also appear. In some cases, leaves develop a whiptail shape, rather than the leaf’s normal wider blade shape. Corn kernels may germinate on the cob prematurely in a last-ditch effort at reproduction. Legumes will have fewer or no root nodules if molybdenum is in short supply.

Again, you don’t know what your plants have access to without an inexpensive, lab-based soil test. Take my word for it, it is worth the effort.

Plum pox is one of the most destructive diseases of stone fruits, and I hope you never see it.

Cabbage and mustard plants are probably not your first thought when it comes to fruit.

As strange as it may seem, the seeds and seed pods of radishes, broccoli, cauliflower, mustards, and other members of the cabbage family produce long, narrow, pod-shaped fruits called silique [se-LEEK]. If you only have one, it is called a siliqua [sil-eh-KWA].

More to pods than peas

Pods are a type of fruit that can be dehiscent or indehiscent. Dehiscent means that the structure opens spontaneously when its contents are mature. If a pod does not open automatically, it is called indehiscent. In either case, pods are made up of two identical long halves and they contain seeds. Those halves are called valves. Valves are the outer walls of the ovary. The two halves are joined along a seam, called a suture. Held between those two halves is a ribbon of seed-bearing tissue called the septum.

Siliquose fruit anatomy

If allowed to bolt, or go to seed, members of the cabbage family produce long, skinny fruits, commonly referred to as seed capsules or seed pods. These pods are each made from two fused carpels. The pods of legumes, such as peas and beans, are made from a single carpel.

If a seed capsule is more than three times as long as it is wide, it is called a silique, or siliqua. If a seed capsule is less than three times longer than wide, it is called silicle or silicula.

​If you allow your radishes and other Brassicas to go to seed, you will see siliquae for yourself, plus you will have seeds for next year’s crop.

Now you know.

How hairy bittercress grows
​
Found pretty much everywhere, hairy bittercress prefers moist soil, open ground, and freshly disturbed areas. Like other weeds, it grows rapidly, often having two generations each year. You may think they have disappeared during the heat of summer but the first autumn rain will let you know that they were merely waiting for wetter conditions. These plants have long taproots.

Hairy bittercress seeds are held in capsules, called siliquae. When the fruit within ripens, there are valves on the siliquae that create a tightly wound coil. That’s why, when you touch them, seeds  explode in every direction. This method of seed dispersal is called ballochory.


Problems with hairy bittercress

Once hairy bittercress takes hold on your property, you will be dealing with it more and more each year, for better or worse. Because of its ability to fling seeds near and far, and grow quickly, hairy bittercress often finds its way into your garden on nursery plants. It is far simpler to put new plants into quarantine and monitor for weed growth right along with pests and diseases.

Before you shrug off this seemingly minor weed, you need to know that the real problem with hairy bittercress is the fact that it can host some nasty diseases. Specifically, tomato spotted wilt and cucumber vein yellowing can be carried into your garden on hairy bittercress. These diseases can have a huge impact on several of your crops, and not just tomatoes and cucumbers.

It is far easier to monitor the ground each spring and autumn for tiny rosettes and then use your long weeding tool to get under the taproot before it takes hold.

You’ve probably read dozens of articles and posts about the wonders of dish soap as a pesticide, fungicide, and surfactant in the garden. All of those posts are wrong.

Over-fertilization is an increasingly common problem in home gardens.

It happens all the time. Your plants start out doing so well. Then they lose some of that vigor. You might see chlorosis (yellowing), cupping, less fruit production, or simply a failure to thrive. What is a gardener to do?

The traditional response was to add more fertilizer, manure, or aged compost. And it would work for a while. Then those same symptoms would return, motivating you to add more fertilizer. And more. And more. Until it reaches the point where no matter how much fertilizer you add, your plants are not performing well. They seem more prone to pest infestations and diseases. How can this be?

Balanced plant nutrients

Just as we must eat a balanced diet to stay healthy, plants need access to a balance of nutrients. Plants absorb nutrients at the molecular level as cations and anions. Those are positively and negatively charged particles, respectively. Too many of one charge makes it difficult for plants to absorb what they need. Also, some minerals, such as iron, are critical components of the absorption process of other nutrients. If there aren’t enough of these nutrients or if they are made unavailable due to an imbalance, your plants can starve while sitting at a banquet. Mulder’s chart provides an image of what those nutrient relationships look like.

Toxic nutrients

Too much of a good thing can be a bad thing. In the same way, too much of a nutrient can lead to toxic levels. Phosphorus, for example, is critical to plant growth and photosynthesis. And it binds tightly to soil particles. Phosphorus toxicity can lead to severe stunting. It can also block the absorption of iron and zinc.

Potassium is critical to enzyme reactions and water and mineral movement within a plant, helps prevent diseases, and regulates the rate of photosynthesis. Potassium toxicity causes leaf distortions, chlorosis, and yellowing along leaf margins. Potassium toxicity can cause calcium, nitrogen, and magnesium deficiencies.

Similar problems occur when there is too much of any nutrient. And these excess nutrients often leach into rivers, streams, and groundwater, causing algae blooms that kill fish and create ripples of pollution and threats to biodiversity.

Too much of any nutrient can throw a monkey wrench in the works. Too much of several nutrients can take years to resolve.

Is your soil over-fertilized?

The first step is to get a soil test. You don’t know what is in your soil without a soil test from a reputable lab. Sadly, those colorful over-the-counter soil tests are not accurate enough (yet) to do you any good. Many universities offer inexpensive soil tests. These tests can save time and money and help your plants be healthier.

Below, you can see my soil tests from 2015 and 2019. In 2015, I learned that the property we bought had been over-fertilized for a long time. Phosphorus and magnesium levels were critically high, and there was too much of everything except iron.

Remember what I said about iron and nutrient absorption? Yep, my plants had been sitting at a feast, unable to get more than a nibble. And it showed. The plants in my landscape were prone to fungal disease, borers, and other insects, and none were thriving.

For four years, I thought I was doing better. I added a little iron. I avoided using fertilizers besides blood meal and ammonium sulfate (for nitrogen). But I continued to add aged compost to help aerate my compacted soil. The majority of that compost was plant debris and chicken coop bedding. It ends up that chicken poop contains very high levels of nitrogen, potassium, phosphorus, and calcium. While my plants needed nitrogen, they didn’t need the other nutrients.

How to correct over-fertilization

Looking at my 2019 soil test results, I realized I hadn’t done enough to correct my over-fertilization problem. I had wasted four years in the process. To resolve the nutrient imbalance, I stopped using compost in my garden. Instead, I saved it for raised beds and container plants.

And that’s the cure - stop adding nutrients. The other half of that cure is to remove nutrients by taking plant material out of your yard completely. Instead of grasscycling, bag and remove grass clippings. Or, you can add them to the compost pile or feed them to your chickens. Avoid using the chop and drop method for a while. Add the following heavy feeders to your garden to use up those excess nutrients: asparagus, beans, beets, broccoli, Brussels sprouts, cabbage, carrots, celery, corn, cucumbers, eggplant, garlic, leeks, melons, okra, onions, parsnips, peas, peppers, potatoes, pumpkins, shallots, squash, tomatoes, and turnips. And harvest those crops within an inch of their lives. Take everything they have to give and get it out of your yard.

Armed with more recent soil test results, I added much more iron to help my plants absorb what they needed. And I switched to using wood chip mulch to counteract my compacted soil. These actions will take time to have an effect. To monitor the effectiveness of these new actions, applying more iron and removing more plant material, I will switch to annual soil tests until soil nutrient levels are balanced.

Your garden may have different issues, but only a lab-based soil test can tell you what your plants need.

Mid to late summer, spores of this fungal disease infect red and purple raspberries. Yellow rust is similar but produces yellow to orange pustules in early to mid-summer.

Late leaf rust symptoms

The first symptom of late leaf rust (Pucciniastrum americanum) is small yellow (chlorotic) spots on the top of older leaves. These spots generally begin appearing in lower portions of the plant, slowly spreading upwards into younger leaves. As the disease progresses, reproductive uredinia form on the underside of leaves, containing masses of spores.

Extreme infestations can defoliate the entire plant. Fruit and flowers can also be infected, which causes them to rot. Of course, if all the leaves have fallen off due to disease, there probably won’t be any fruit or flowers. If the fruit has already formed, late leaf rust will appear as tiny orange spots on individual drupelets. Affected fruits will also ripen unevenly.

Late leaf rust lifecycle

Spores of this disease overwinter in white spruce and infected raspberry canes. Wind can spread these spores, so your upwind neighbor’s raspberries can directly impact yours.

Late leaf rust control

Like other rusts, late leaf rust is best avoided by pruning plants for good airflow and avoiding overhead watering. Also, be sure to remove spent canes each year. Throw infected plant material in the trash, not the compost pile.

​Fixed copper sprays may help prevent and treat late leaf rust.