Drought can wreak havoc on farms and mature trees, but gray water can be used to reduce the impact on your yard. According to UC Davis, "Gray water is untreated waste water which has not come into contact with toilet waste." This includes water collected from the shower, bath, washing machine, or sink.

You should check with your local authorities to learn about specific restrictions on the use of gray water in your area. Gray water should never be considered potable (safe to drink). Personally, I avoid using it on food crops, but it does wonders on ornamentals, trees, flowers, and the lawn without wasting fresh drinking water.

I discovered a new bug while pulling weeds under one of my apricot trees this morning.

​It is 1/4" long, somewhat flattened, and it has a distinct light green triangle on its back. After a little research, I learned that it is called a Lygus bug.

According to UC Davis, Lygus bugs (Lygus hesperus), also known as western tarnished plant bugs, or just plain tarnished plant bugs, are a serious threat to strawberry growers, causing "irregularly shaped, cat-faced strawberries". Getting rid of Lygus bugs is tricky. Most pesticides available over-the-counter are ineffective on adult Lygus bugs and can be devastating to natural enemies of spider mites. 

The best organic solution is to reduce the number of weeds in your area and to be alert, squashing the Lygus bug whenever it is spotted. There is a commercially available parasitic wasp, Anaphes iole, which attacks lygus eggs, but its effectiveness is thwarted by the fact that new Lygus bugs can enter the area repeatedly

​New research in the use of trap crops is being explored. I’ll keep you posted!

​It's a war zone out there!

It took plants 50 million years to develop roots as we know them today. Everyone knows that roots provide anchorage and access to water and minerals in the soil. But they do far more than that!

• Fine root hairs use chemical messaging to communicate a plant's needs to nearby soil microbes
• Root plant cells synthesize hormones
• Roots secrete sugars, acids, and amino acids that protect against pathogens and stabilize nearby soil aggregates
• Root systems reduce and prevent erosion
• Some types of roots help aerate plants growing in wet conditions

First root

The first structure to emerge from a sprouting seed is called the radicle. The radicle becomes the primary root. If the primary root continues to grow and develop, the plant will have a taproot system. Carrots are taproots. If several smaller roots develop, the plant will have a fibrous root system. 

Adventitious roots may arise from stems, branches, or leaves. These opportunist roots come in a variety of growths, such as buttress roots, aerial roots, and stilt roots. ​

Storage roots

There are also storage roots. Beets, carrots, ginger, horseradish, licorice, radishes, rutabagas, sassafras, sweet potatoes, and turmeric are all storage roots. You may think that regular potatoes are a root crop, but they are not. Potatoes are tubers, which means they are the starch storage structures for rhizomes, or underground stems.

​Root structure

Unlike twigs and stems, which have regular branching patterns, roots start out large and then divide, repeatedly and randomly, getting progressively smaller, in their search for food and water. At the end of each root is a root cap. The root cap is like a hard hat, worn to protect the growing meristem tissue, as the root moves through the soil, looking for water and mineral nutrients. Behind the root cap is where cell division takes place. As these new cells are produced, the root cap is pushed forward. As more new cells are produced and the root moves forward, these older cells stretch and create storage pockets called vacuoles. This is called the zone of elongation. Finally, growth and elongation are complete and root hairs can begin to emerge. This is called the zone of maturation.

​Root damage

Transplanting and repotting plants often shears off a large number of these root hairs. This is what causes the initial wilting. Rather than tamping down your transplants, try mudding them in to protect those important root hairs.

​Tree roots can damage sidewalks, patios, and your home’s foundation, so plan ahead before installing trees and large shrubs. Poor health or branch die off on one side of a tree or large shrub can often be directly linked to damage to the root system from construction, digging, or heat islands.

Tree roots

We used to think of tree roots as going down, down, down, into the Earth. In some cases, that is accurate. One tree in the Kalahari desert has a root system believed to be over 220 feet deep, but, in most cases, tree roots don’t look anything like that. Tree roots are most easily pictured as a goblet set on top of a dinner plate. The goblet represents the aboveground portion of the tree while the shallow, far-reaching dinner plate represents the root system. Very often, a tree’s root system is 4 to 7 times the diameter of the aboveground portion. Trees are often classified using a ‘root-to-shoot’ ratio. This ratio refers to the weight of the aboveground portion of the tree to its below ground growth. Normally, this ratio is 1:5 to 1:6. This means that the 5,000 lb. tree you see probably has a root system that weighs over 1200 lbs.

The majority of a tree’s root system is found in the top 18 inches of soil. This is why trees fall over when the soil gets waterlogged. Trees growing in heavy clay soil, such as we have in San Jose, California, tend to have smaller root systems. This is because clay soil holds far more water and nutrients than other soil types.

Root depth

Most garden plant root systems are relatively shallow. Rooting depth of garden vegetables can generally be classified as:

• Shallow (12” to 18” deep) - garlic, lettuce, onions, peas, radishes, spinach, zucchini
• Medium (24” to 36”) - beans, beets, cantaloupes, carrots, cole crops, cucumber, eggplant, peppers, potatoes,
• Deep (> 36”) - chard, sweet corn, lima beans, melons, parsnip, pumpkins, rhubarb, winter squash, tomatoes, and asparagus​

What does all this mean?

This means that it can get crowded down there, if you are not careful. If you have deep raised beds, save them for the medium-sized root systems. Most deep-rooted perennials are best planted directly in the ground. The most shallow-rooted plants can often be grown in containers.  Root depth also plays a big role in how drought tolerant a plant can be, and how deeply they need to be watered.

Root pests and diseases

Root systems are subject to specific pests and diseases. Common root diseases in California include:

• armillaria root rot
• aster yellows phytoplasma
• damping-off
• fusarium crown and root disease
• phytophthora root and crown rot
• root rot

Peach root knot nematodes, crown and root aphids, root weevils, flea beetle larvae, and root borers are just a few of the garden pests that attack root systems.

When removing plants from your yard or garden, it is best, whenever possible, to cut the plant at ground level and leave the roots in the ground. As the roots decompose, they will feed the local soil microorganisms, which will migrate, over time, to help another plant thrive.

Whatever type of root system your plants have, good soil health and soil structure are critical to plant health. 

Keyhole gardening is a method developed for areas experiencing severe drought and limited resources, specifically Africa. However, the concept is just as useful in other parts of the world and in your backyard. Keyhole gardens conserve water, and they provide plants with easy access to nutrients.

Keyhole gardens are a variation on raised bed gardening. Keyhole gardens are round raised beds that feature a notch in one side that provides access to a composting tower, or basket, in the middle. As compostable materials and water are added to the center of a keyhole garden, the water and nutrients spread out within the keyhole garden to feed and irrigate your plants. The loose, nutrient-rich soil makes it easy to grow edibles in even the worst conditions.

How to build a keyhole garden

Keyhole gardens are easily made with curb-scored old bricks, stones, or cinderblocks.  You can also use landscape cloth, wood planks or branches, wine bottles, old fencing panels, corrugated metal sheets - really, you can use anything that isn’t toxic. Use your imagination! Follow these steps to create your very own keyhole garden:

1. Mark off a 5- to 8-foot diameter circle on some flat, cleared ground. You can do this by tying a string to a stick or tool stuck in the ground in the middle, measuring out the proper distance, and then using the end of the strong as your guide to score the circle in the ground.
2. In the center of that circle, mark off a 12- to 24-inch circle, using the same method.
3. Dig a slight trench along the line of the larger circle, the width of your wall material.
4. Mark a triangle in the soil from the larger circle to the inner circle. This is your keyhole.
5. Build a central basket with a section of hardware cloth, chicken wire, or woven sticks.
6. Place a thick layer of straw or shredded paper in the bottom of the basket, and then fill with alternating layers of compost and straw or paper, watering as you go.
7. Create a short wall in the outer circle using bricks, stones, or whatever material you have available. [If you use a wall material that is compostable, you may want to line it with heavy duty (4 ml or more) plastic to prevent it from being broken down.]
8. Cover the bottom of your keyhole garden area with a layer of sticks and stalks, no bigger around than a broom handle, and no longer than a foot, about 5 inches deep at the basket and tapering down as you move outward. [This is a great way to put all those sunflower stalks and corn stover to good use!]
9. Cover the stalks with an inch and a half of wet straw. This completes your drainage layer.
10. Fill the outer circle with layers of topsoil, compost, and straw or shredded paper, banking the material up against the basket, and then water deeply.
11. Build up the wall and continue filling and watering until you have reached a height that is comfortable for you. 
12. If you live in an area with a lot of rain or strong sunlight, you may want to add a protective roof over the basket.
13. Plant crops in concentric circles, within your keyhole garden.
14. Add compostable materials to the basket as they become available and then water.

Sources of compostable materials

Most people know that yard and kitchen waste are compostable, but there are many other sources of perfectly acceptable materials for the basket of your keyhole garden or any compost pile. Remember that compostables are designated as “browns” or “greens” and that you should aim for a 50:50 mix of the two. Some interesting source of “green” compostables include coffee grounds and tea bags, often available for free from coffee shops, and fresh manure from local barns. [Manure from veterinary clinics is not recommended.]

​We throw away a profound amount of compostable “brown” material. Some sources you may not have considered include any paper or wood products (simply avoid the colored, slick, or waxed varieties), dryer lint, vacuum cleaner waste, shredded, unwaxed cardboard,  and even clothing made from 100% natural fibers. Rather than adding these materials to local landfills, you can transform them into plant or worm food in your compost pile, worm farm, or in the central basket of your keyhole garden.

Building a keyhole garden can help you get around the problems associated with heavy clay, compacted soil, and difficulties bending over. Check out this video about a heart-warming solution to starvation around the globe and  a fun new way to grow edibles in your own backyard!​

Invasive plants are those non-native plants that infest an ecosystem. Unlike normal weeds, which have evolved within a specific ecosystem, invasive plants generally do not have any natural enemies, so they grow out of control. They use up water and nutrients, pushing out local flora and fauna. Some, such as Scotch broom, can be poisonous to your pets.

Invasive plants are often introduced to your yard on purpose, by buying and planting something just because it "looks nice”. According to the UC Davis IPM (Integrated Pest Management) page: a 10,000 acre infestation of giant reed (Arundo donax) on the Santa Ana River in Orange County is estimated to use 57,000 acre feet more water per year than native vegetation. One group, PlantRight, has developed a list of invasive plants that should be avoided. Another group, Calflora, offers extensive lists (with photos) of plants that are invasives and plants that are under consideration as invasives.
​
Taking the time to plant species that are native to your area reduces water waste and prevents the disruption of the natural lifecycle of countless plants and animals.

Cabbageworm description

Cabbageworms start out as tiny yellow, green, or white, rocket-shaped eggs that are laid singly on the undersides of leaves. If you have a hand lens, you can see distinct ridges on the eggs. Whether you can see that well or not, do your plants a favor and extermigate the eggs whenever you see them.

Sheet mulching is touted as one of the easiest ways to reduce weeds in your yard or to get rid of a water-hungry lawn and replace it with something more drought-tolerant. (Solarization is a more extreme method that can rid an area of many fungal diseases, as well as weeds.)

To sheet mulch an area, trim any current plant growth to the lowest possible height, water the area (to provide for soil microbes) and then cover the area completely with a 4" layer of wood chips.

We used to urge people to cover the area with layers of newspaper or cardboard, but then we learned that those materials attract voles and termites. Those layers also interfere with evaporation, percolation, and gas exchanges. Your local tree trimmer will be happy top give you a truckload of fresh wood chips, perfect for blocking weeds and protecting your soil.

For free.