Last time I discussed bulbs that bloom is late summer as opposed to the usual spring bloomers. A couple of readers wanted to know when to plant their summer and fall bloomers, and the answer is: it depends. Bulbs or corms for plants that are cold hardy can be planted as soon as the ground can be worked. This includes lilies, summer-blooming daffodils, gladiola, allium and the like.
More tender bulbs need to be held back a bit before you plant them. Examples include dahlias, caladiums and calla lilies. These can go into the ground a month or so before the last freeze is expected, since they usually take several weeks to develop the root systems and push up above the soil line. Keep an eye out though for late freezes and make sure they get some kind of protection from frost if they pop up before summer has come to stay.
True fall bloomers are often only available in mail order and will arrive in summer. The beauty of this is that they bloom in a matter of weeks, so the gratification comes along soon.
Now, for bulbs, tubers, and corms that bloom even later than those mentioned last week.
Colchicums are commonly referred to as autumn crocuses. This plant pushes up leaves in the early spring that die back in early summer. In the fall they produce white, pink or purple crocus-like blooms. These corms should be planted as soon as you get them as they may begin to grow before reaching the soil otherwise. They prefer full sun to part shade. They are a good choice to plant with vinca, and should be planted in clumps 2 to 3 inches below the soil surface.
Another choice is a corm called Showy Crocus. This plant produces white or blue blooms in September or October. They prefer well draining soil and do well in full to partial shade. Show Crocuses are best massed in a perrenial bed in a grouping of 25 or more.
Another great plant is magic lily, which I wrote about last summer.
Cyclamen is another option. you’ve probably seen it in the grocery store
floral department around Christmas time. In warmer climates it booms during the winter. In Utah it is a late-fall bloomer. Some cyclamen are spring blooming, while other varieties are fall blooming, and both go dormant in the summer, so early planting is a good idea.
Also a great option for warmer climates is amaryllis–typically associated with Christmas. Mine will only bloom in a pot inside, but if you live in the South, you may find this a terrific addition to you fall garden.
On an unrelated note: If you are experiencing a nice break from winter weather, now is the perfect time to prune rose bushes and other woody plants that need a hard pruning. Doing this before the spring leaves come on will prevent the bush from putting valuable strength into producing leaves on a branch you will later remove. I need to tackle not only my roses, but my Russian sage and butterfly bushes this weekend.