Sweet Alyssum

Sweet alyssum is a lovely, low maintenance flower that attracts butterflies, but it isn’t actually an Alyssum.

Sweet alyssum

Not so long ago, when scientists first started using DNA to sort out plant species and plant families, a number of embarrassing relations and non-relations were discovered. This has lead to upheaval in the world of plant nomenclature. While this doesn’t generally affect us, as backyard gardeners, it can cause some confusion when it comes to plant names. So it is with sweet alyssum.

Native to the Mediterranean region, dainty sweet alyssum used to be counted among the Alyssum species. As such, it was known botanically as Alyssum maritima. [Isn't that a lovely name?] We now know that the global sweet alyssum plant is actually a Lobularia species, an equally pleasant name.. Again, this doesn’t make much of a difference for us, as home gardeners. What I was surprised to learn is that, in both cases, sweet alyssum is a member of the cabbage family, which means that it might attract the same pests and diseases as your cabbages, broccoli, and mustards. Before we start ripping out this tiny, durable flower, let’s see what it has to offer.

Sweet alyssum growing along raised bed

Sweet alyssum description

Each sweet alyssum plant grows up to 12” tall and wide. Stems are made up of several branches, each of which has many flower clusters. Most sweet alyssum flowers are white, but you may get an occasional blue, pink, or purple in the mix. These flowers have a honey sweet aroma that bees and other pollinators seem to love. As individual stems near the end of their life, a profusion of fruits, which are hairy elongated pods, like most other members of the cabbage family. Each pod contains two seeds. These seeds spread easily on the wind. And plants can thrive in a number of different locations.

How to grow sweet alyssum

Sweet alyssum somehow manages to grow in rocky outcrops, on sand dunes, between paving stones, and everywhere else seeds can get a toehold. This is good news. Unlike their perennial Alyssum cousins, sweet alyssum is an annual. If you have it growing already, you know that it readily self seeds.

If you know anyone who already has sweet alyssum growing, simply ask them for some clippings. Lay the seed pods where you want sweet alyssum to grow, cover it up with just a tiny bit of soil, keep it somewhat moist until germination occurs, and you will have sweet alyssum for life.

​While these plants prefer partial shade, they are surprisingly tolerant of heat and drought, making them an excellent choice for areas with scorching summers.

Sweet alyssum seed pods

Sweet alyssum is an excellent choice for softening paths, lining the edges of raised beds, or as a relatively maintenance-free ground cover. I say ‘relatively’ because sweet alyssum plants may get leggy and flop over near the end of their productive lives, leaving them to look somewhat less appealing. You can eliminate this look, and stimulate new flower growth, by occasionally giving plants a trim. I use my weedwacker.

Sweet alyssum pests and diseases

As far as cabbage family members go, sweet alyssum is rugged. It has very few problems. Diseases that may impact your sweet alyssum include botrytis blight (gray mold), clubroot, downy mildews,  and root and crown rots, though I have never seen any of those diseases on my sweet alyssum while the same diseases have, at times, been present on nearby plants. Supposedly, the cyclamen mite and caterpillars of the diamondback moth feed on sweet alyssum. Again, I have not seen this in my garden. The only pest that I have seen hiding out, under the canopy of sweet alyssum blossoms is the dreaded Bagrada bug. ​​

Bagrada bugs travel in large groups and they love to eat plants in the cabbage family. This includes your arugula, broccoli,cabbage, cauliflower, collards, kale, nasturtiums, radishes, rutabagas, turnips, and watercress. Bagrada bugs also feed on beans, capers, corn, melons, millet, okra, papaya, peas, peppers, potatoes, soybeans, strawberries, tomatoes, and wheat, so don't ignore them! Having only arrived in California in 2008, this pest has few natural enemies and can cause considerable damage in the garden.

Bagrada bug (Davefoc) CC BY-SA 3.0

Rather than ripping out your sweet alyssum, just trim it back every once in a while and be sure to take a peek underneath its skirts every once in a while, with an eye for Bagrada bugs.