For spring and early summer “sunshine,” consider the hardy alyssums. Plants can be used that are from three to four inches to a foot in height. Most of them are in a yellow color range.
On dark cloudy days, yellow-flowering plants appear to be cheerful blotches of sunshine in the garden.
The paler yellows are almost as good as white, any day, to settle color quarrels between plants, to prevent color clashes, or to brighten a dark corner.
They may be used as edging plants along sunny borders… they are ideal for sunny rock gardens or rock walls or in any well-drained location in full sun. They bloom less freely if subjected to any amount of shade. Wet locations lead to the rotting of roots.
The best known is Alyssum saxatile.
Its many common names demonstrate its great popularity like Alyssum carpet of snow, golden tuft, gold dust, and rock madwort. A plant grows 10 to 12 inches high.
The grayish foliage is persistent… the leaves cling to the stems all winter even when withered.
In the spring the plant becomes a mass of gold when the clusters of buds open into small yellow heavily scented flowers that completely conceal the foliage.
When the plants have finished blooming, unless seeds are desired, it is best to shear them back rather severely to prevent seed formation. They may continue to send up a scattering of new blossoms during the summer.
The stems are somewhat woody and gardeners occasionally report that the plants die after blooming, or rot away during a wet winter. If trouble of this kind occurs, try putting a gallon or two of soil over the middle of the next plant you get.
Do this after it finishes its big blooming period in the spring. Shake most of the soil down among the branches. This seems to excite the plant into new growth. It makes new rootlets which give it a new lease on life.
When happily established. the plants will live for years and each spring they are literally a “basket of gold” at tulip time. Sprigs are lovely in vases in combination with some of the spring blooming bulb flowers,
Growing Alyssum Plant from Seeds
If more plants are desired, a few seeds may be allowed to mature. If you have experienced trouble in getting the seeds to germinate, try planting new crop seeds as soon as they are mature. Plant the seeds in a flower pot or flat.
Germination is fairly rapid and wonderfully easy at that time if the soil is kept moist and shaded until the plants are up. Since the seeds are thin, one needs only a bare layer of soil over them.
The plants rather resent being disturbed, but when they commence to crowd each other in the flat, they can be set into pots. After the transplanting has been finished, sink the pots in a shady spot where the plants can go right on growing until the following spring.
Like any other kind of transplanted seedling, one must water them when necessary. In early spring it is easy to dig up each pot and plant it in its permanent location.
You will probably find that roots are growing out in all directions right through the pots. The plants will bloom the first spring. If they are in a favorable location they will be a joy for many years to come.
Plants do not always mature seeds, or if it is a hybrid variety, it may not come true from seeds. In that case older plants may be divided in early spring or cuttings may be taken after the plant has blossomed.
Remove the lower leaves and plant the cutting in a pot. Sink the pot to the rim in a shady location, and place a glass jar over it. When the cutting has rooted, the jar is removed. The plant can be reset the following spring.
In looking through seed, nursery catalogs and websites, one finds quite a number of varieties of Alyssum saxatile. The variations are in height and shade of yellow.
‘Compactum’ may be exactly the same or very similar to Alyssum saxatile as the height given in different catalogs and websites is not consistent… it varies from eight to 12 inches. “Flore-pleno” is the double form, very bright, showy and in blossom for a long time.
Species of Alyssum
Alyssum saxatile ‘Citrinum’ is a paler yellow than saxatile but with the same habit of growth. This color blends in beautifully with pink or lavender tulips.
Alyssum montanum may grow from three to four inches in height or as much as eight inches. The yellow blossoms are fragrant and appear a little later than saxatile. Alyssum alpestre blooms in late spring and early summer. The spreading mats of soft yellow are three to four inches high.
Alyssum argenteum may grow up to 15 inches with silvery leaves. The clustered heads of deep yellow flowers appear later than saxatile and continue on through the summer. Alyssum spinosum has silvery foliage. Spiny flower branches grow a foot tall.