Posts from — May 2009

More charmingly known as Butter-and-Eggs, the common name “Toadflax” applies to several similar species. All sport cheerful yellow flowers resembling snapdragons, to which they are related. Two-foot tall clumps of smooth green stems are covered with narrow, pointy leaves two and a half inches long. The flowers appear whenever growing conditions permit.

Originally imported from Eurasia as ornamentals, the plants quickly escaped cultivation and are featured on many wildflower posters. Unfortunately, Toadflaxes are now officially listed as noxious weeds. As such, it is illegal to grow them or sell their seeds.

You will quickly understand the “noxious” designation when you go to kill these weeds. Seeds germinate in spring (I’ve already noticed sprouts appearing in my garden) and quickly grow into small plants with no flowers; most early growth is underground. Taproots penetrate three to ten feet while lateral roots sprout into new plants several yards away. By the time flowers finally appear, control is extremely difficult. Make sure to remove blossoms before seeds form. Try a combination of digging, spraying with an herbicide, and “frustration” (continually removing top growth until the roots give up). Victory may take years of unrelenting effort.

True snapdragons are a welcomed addition to any landscape. Just don’t be fooled by these imposters!

Appearance

With violet-blue blossoms scattered across a field of emerald green, Dwarf Periwinkle is a popular groundcover in the Pikes Peak region. Also available in white and purple-red, these 5-petaled pinwheel-shaped flowers bring welcome color to a shady spot. The shiny leaves are arranged along stems that may reach three feet in length, but are only six inches high. The stems will root wherever they touch the ground.

Cultivation

Dwarf Periwinkle requires partial to full shade; the leaves develop chlorosis and the plant declines in full sun. It does best in fertile, well-drained loam, but will tolerate less-than-optimal conditions. While preferring damp soil, established plantings will endure some drought. Allowing the foliage and soil surface to dry between waterings helps prevent Vinca Stem Blight, a fungal disease brought on by constantly wet conditions.

Landscape use

Because it competes successfully with tree roots, Periwinkle is frequently used as an evergreen groundcover under woody plants. The trailing stems are also attractive spilling over the sides of flowering containers.

Basket of Gold (Aurinia saxatilis) is a long-lived, low maintenance ground cover for small spaces such as along walls or paths, or in rock gardens. Gray, slightly fuzzy leaves are present year round, forming clumps 6 to 18 inches tall and 6 to 12 inches wide. In early Spring the plants are totally covered with masses of tiny cross-shaped flowers. Eye-catching colors range from soft yellow ‘Citrina’ or ‘Dudley Neville’ to the intense golden yellow of ‘Gold Dust’.

Easy to grow from seed, Basket of Gold prefers sandy, infertile soil, but will tolerate any location that is well-drained. Water needs are low to moderate; full sun is required. The plants are hardy to 9,000 feet. To keep the clumps from becoming rangy, they should be cut back immediately after blooming.

Suggested companion plants include Creeping Phlox (Phlox subulata), Candytuft (Iberis), and the low-growing Veronicas, whose blue flowers provide the perfect contrast.

Soil is the foundation of your garden. It pays to invest in creating the best possible soil for your plants to grow in. Living along the Front Range of Colorado’s Rocky Mountains has many benefits. However, no one would move here for the black topsoil! Instead of the optimal 5% humus content, most of our soils have little or none. It’s up to us to improve on Mother Nature.

You can easily increase the percentage of organic matter in your soil by adding compost or another organic amendment. This added humus will act as a sponge, increasing water retention in sandy soils. On the other hand, in clay it acts to improve drainage by increasing the size of air and water spaces. Plus, organic matter works with your fertilizer by holding nutrients in a form that is available for absorption by roots. As you can see, organic matter is an important component of healthy soil.

It’s best not to add too much organic material at once. Many organic amendments are based on manure, and could contain harmful amounts of salt, as well as weed seeds. Plus, the nitrogen in fresh manure can burn tender roots. Make sure to let manures age before adding them to your garden. Decomposition requires nitrogen. Any form of organic matter that isn’t completely decomposed will steal that essential element from your plants.

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Dirt is fascinating. Oh, I know, you’re thinking of the dirt you wash out of your clothes, or off your car. I don’t find that kind of dirt very exciting at all. But the dirt in a garden is a whole ’nother story!

Actually, dirt is just one component of what gardeners prefer to call “soil.” Rocks weather and break down into smaller rocks, pebbles, gravel, and finally sand and silt. These tiny particles mix with organic matter—decomposing plants and animals—called “humus.” Then there’s air, and water. Add in weed seeds, worms, bugs, and a huge variety of microorganisms, and you have the living stuff in which we plant our gardens.

Soil has various names, according to the particle sizes of the minerals involved. Coarse grains are sand, while the finest dust becomes clay. In between there is loamy sand, sandy loam, sandy clay, loam, loam, silt loam, silt, silty clay loam, clay, clay loam, sandy clay and silty clay. You can see how it all works in this chart by the U.S. Dept. of Agriculture:

If you are curious as to what kind of soil you have, an easy test is to mix about a third of a cup of soil into a jar of water. Shake it well, and watch while the particles settle. Sand sinks quickly to the bottom, while the finer silt and clay particles may remain suspended for several days. When the water is clear, you’ll have a cross-section of particle sizes.

Most plants prefer a loamy soil containing about 5% organic matter, and equal amounts of air and water, about 25% each. However, very few parts of Colorado have such soils. More typically, we find ourselves dealing with either sticky clay or porous sand. Organic matter is often nonexistent.

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Peas and carrots are a classic couple in the kitchen, but what about the garden?

Normally, peas are sown in early spring. The traditional date is St. Patrick’s Day. While that may work in gentler climes, at 7,000 ft. elevation, I would need a drill to create holes in my frozen ground. I usually plant a month later, on Tax Day. At least it gives me something to enjoy on that date.

This year, weekly snowstorms have delayed all my gardening chores. I finally got my peas into the ground on May 6. I don’t have great expectations for the harvest. Maybe we’ll have a cool start to the summer, and my husband will get to enjoy his Sugar Snaps. Maybe not. That’s the gamble of gardening in Colorado.

Carrots, on the other hand, are usually planted a week or two before the average last frost date. The cool temperatures and snow-damp soil help keep the seeds from drying out during the three weeks it takes them to germinate.

This year, I sowed carrots on the same day as the peas. At least they’re right on schedule. I took the time to arrange the seeds in blocks of 16 per square foot, so I won’t have much thinning to do later. In my 4 x 4 foot carrot bed, that gives me 256 carrots—plenty for our needs.

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Now that you know why you want a lawn, and how big it should be, it’s time to consider what type of grass to grow.

Bluegrass

Kentucky Bluegrass still reigns supreme for a turf that can stand up to hard use. It spreads via runners, so it quickly fills in holes. (But beware. Those same runners have a tendency to wind up in the adjacent flower beds.) If you have children and/or dogs, this is probably your best choice.

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