Q I am considering planting Shirley poppy seed in the treeboxes around my block. However, I am not sure if it is legal to plant poppies in D.C. and have no desire to unexpectedly entertain federal agents in April. Is it legal to plant poppies in the garden?
A There are no worries with planting Shirley poppies, Papaver rhoeas. Only the opium poppy, Papaver somniferum, is regulated as a narcotic. The opium poppy has a number of uses, both benign and narcotic. It is known too as bread poppy and its seeds show up on the surface of bagels. It also has attractive flowers and interesting seed pods, used in dried flower arrangements. There are many lovely double-flowered kinds.
Some seed dealers state that they cannot sell it in our country, while others sell it without mention of its potential for narcotic production. It is still widely grown ornamentally by gardeners who have no idea that it is the same species as the opium plant. This may be because some seed dealers sell it as Papaver paeoniflorum. This name is not correct but is frequently used in reference to the double types.
The Shirley poppy, the poppy of Flander's field in Belgium, is easy to grow and often used in highway plantings. They need good drainage and prefer soil that is not too fertile.
Here's the rub: The seed is best sown in the fall, to allow the plant to grow a little before winter and then bloom the following season. Another problem with the Shirley poppies in our region is that they bloom and die rapidly due to the heat in June. If you are determined to plant them, and there are some lovely varieties, I would recommend getting fresh seed this summer and sowing them in early October for a show the following year. If they are grown in a favorable location, they may sow themselves for several years.
We have a wooded area that is cleared of undergrowth. We planted azaleas, hydrangeas, bulbs, periwinkle and, in some areas, ivy. We put down pine nuggets throughout the area to help prevent weeds. My wife and I disagree, however, about fallen leaves.
I prefer to leave them on the ground, thinking that they will act as a blanket to protect the plantings' root systems during the winter. In the spring I suggest that we blow them off or lightly rake them off so that we see the mulch during the spring and summer. My wife says that the leaves will smother the root system so they can't get air and she doesn't want to hide the mulch. I also contend that the leaves will help earthworm activity.
In a woodland garden, there is no compelling reason to rake. There are some exceptions, however. If you want to grow early spring wildflowers, most of the leaves should be removed, particularly if they are primarily oak or beech leaves, which are slow to decay. This will prevent any struggle that the wildflowers might have in pushing through leaves to reach the spring sunlight. If you are dealing with maple leaves, there is probably no need to remove them, since they are thinner and decay more quickly. Leaves do not smother the root system of trees, but they might offer some protection to voles intent upon eating the roots of your shrubs. If you have not had any problem with voles, let the leaves lie. Your pine nuggets will soon decay themselves and lose their visual appeal.
The leaves will not harm any of the plants you mentioned. And yes, they will draw earthworms to the surface, which will hasten their beneficial decay.
I'm in need of help in pruning my Scotch broom. I fear they have never been correctly pruned, just trimmed, and I'm very eager to get them done properly.
Pruning the ends of the branches will only make your Scotch broom grow unnaturally dense and will give it an odd appearance. It is almost never a good idea to shear any shrub, no matter how strong your urge is to make it appear tidy.
Like most shrubs, pruning is simply a matter of cutting some of the oldest branches back to a point just above ground level. This is indeed best done just after the flowers have faded in spring because pruning at any other time may remove flower buds.
Scott Aker is a horticulturist at the U.S. National Arboretum.
