When should fall cleanup begin?

By By Amelia O’Brian / horticulture columnist
Nov. 23, 2003
Dear Gardener: You have mentioned fall cleanup in the perennial garden before. When is this supposed to take place and what exactly does it entail?
Dear Reader: Fall cleanup should occur anytime after a hard frost, but before really cold weather hits. It does not really involve too much. You need to cut back most perennials; some don't require this attention. This is also the time to remove all summer annuals if you have not already done so. Go ahead and plant pansies and bulbs, if you have not already. Once that has all been done you need to apply some type of mulch. You can go the natural route and cover the area with leaves or you can go with purchased mulch. If you decide to go with purchased (wood) mulch, remember not too apply it too thickly. An inch or an inch and a half is definitely enough mulch.
Leaves make a fantastic winter mulch (cheap too). Just remember that they will need to be removed in mid spring to allow the perennials to emerge. If you wish to apply a pre-emergent herbicide, you will need to do this before putting down the mulch of your choice.
Dear Gardener: I have a hosta that is several years old and quite large. My sister is insistent that I need to divide it this fall. She says that it is for the health of the plant. But, I have not seen any decline in it and I think she just wants a piece of it. Should I give in and divide the hosta? Will it damage it to do it now or should I wait till spring?
Dear Reader: If the hosta has not been divided in more than three years, it probably does need to be separated. Even if you have not seen any decline in vigor, you surely will soon. Fall is the perfect time to divide any perennial, not just hostas. If you wait till spring, you risk damaging new growth when you cut it apart.
Dear Gardener: I recently saw some orchids on sale at a chain store. There were only a few that were marked down about half price. The rest of the orchids were in a separate display and they were full price. Do you think the half-priced ones were diseased? If not, why would they be discounted while the others weren't?
Dear Reader: Most likely the full price orchids were part of a recent shipment. The 50 percent off orchids were probably left over from earlier in the season. Their flowers were probably done or almost done with their display. An orchid in bloom is much easier to sell that one that is not. If the orchids were diseased, I seriously doubt if they would be in close proximity to the new shipment. Overall, unless the orchid was intended as a gift, an out of bloom orchid is a good buy. It will come back into bloom in a couple of months, if given the proper care.
Dear Gardener: The other day I fertilized my mums that are in pots. The next morning they were dead. What did I do wrong? Do you think the fertilizer was too strong?
Dear Reader: You did not mention how dry your mums were at the time of fertilization, but I suspect that they were very dry. Never fertilize anything when it is overly dry, even if the fertilizer is not mixed at full strength. If you need to, water the plants first then make an application of fertilizer. I always water my potted plants, at least a little bit, before fertilizing. I like to fertilize annuals that are in the ground after a good rain. This assures that the plants are not absorbing too much fertilizer at one time.