â€œI have a very large witch-hazel â€˜Pallida.â€™ It produces two different kinds of flowers. The showy, large yellow flowers are present on about half of the branches, all on one side. On the other side there are much smaller, rust-coloured flowers that are virtually invisible. Does witch-hazel have separate male and female flowers? If pruning is advised, when can it be done?â€
Ruth Foster, Belcarra
Your witch-hazel is suckering from the rootstock. Usually the rootstock chosen for flowering witch-hazels is the medicinal Hammamelis virginiana which is still used today by herbalists. Itâ€™s also popular with commercial growers, because itâ€™s far more vigorous than the flowering ornamental witch-hazels.
Used as a rootstock, H. virginiana makes flowering witch-hazels grow faster so that commercial growers can keep their prices down and produce good sized trees available for sale sooner.
Suckering problems arise later, when people prune branches of the flowering witch-hazel, stimulating the rootstock to use its excess energy by thrusting up its own stems.
Ruth will need to prune away the rootstock branches. They emerge below the graft, and in fall and winter they usually hang on to more of their leaves than the ornamental branches do. Pruning is best done in the dormant season.
Unfortunately, pruned suckers usually recur, but itâ€™s possible to avoid major pruning of suckering branches by checking the tree often and pulling (not cutting) any new below-graft buds away from the stem.
That usually removes the growth node the suckers sprang from. The nodes are tough, so itâ€™s best to pull with pliers or another grabbing tool.
Many other grafted shrubs and trees can sucker. Itâ€™s more likely after heavy pruning or winter dieback of the top growth. Contorted hazel, tree peonies, and roses are among susceptible species.
â€œWill you please tell me what vegetable seeds I can sow indoors for the coming few months?â€
In January and February: leeks, storage onions, sweet onions, celery and parsley.
In March: lettuce, cauliflowers, broccoli, fennel, cabbage, peppers, asparagus and at the end of March tomatoes.
In April: eggplant, squash, pumpkin.
There are lots of vegetables you can plant outside from February on, but these are the ones usually started inside in spring.
â€œHow can I keep my orchid re-blooming. I have followed instructions carefully but nothing has happened.â€
Mi Vuong, Vancouver
How long has been since the orchid last bloomed? Few orchids bloom continuously. In the wild, most bloom once a year, then rest while they build strength for a second flowering. Grown in pots in the house, orchids tend to follow the same habits.
Orchids grown commercially for sale may be forced into bloom at a time thatâ€™s unnatural for them. Such orchids will need a longer than normal period to regain their strength.
Iâ€™d recommend patience: give the orchid lots of loving care, according to the instructions. Try double-checking any instructions in case thereâ€™s some extra point (more humidity, perhaps) that would make the orchid even happier.
Anne Marrison is happy to answer gardening questions. Send them to firstname.lastname@example.org