Q: How can I avoid weeds from mulch? This year, I mulched with hay, and nothing but weeds was there when I removed the hay in late spring.
A: This year, choose salt marsh hay instead. It has far fewer weed seeds than barn hay. If you don't work so hard next spring and only cultivate 2 inches into the soil instead of deep digging, the seeds will gradually die off. Every year you dig deeply, you are churning up more seeds to the surface, where they can find light and sprout.
It is estimated that the germination rate of weed seed declines 50 percent to 75 percent each year when cultivation is shallow rather than deep. Imagine how many fewer weeds that would be in just three years!
Q: You helped me once before with my Christmas cactus. Now I hope you can help me with my rosemary. First of all, is it an annual or perennial? Last winter, my plant hardly survived. I have a new plant now and want to know what I can do to protect it over the winter.
A: Rosemary is an annual in this zone but can tolerate an occasional drop in temperature to near freezing. So run, don't walk, into the garden and pot up the rosemary. It makes a lovely houseplant during the winter if kept on a sunny window or under a plant light. Make sure ventilation is good to help to prevent the powdery mildew that often coats the leaves. Be careful not to overwater.
Outdoors, you have a slim chance of saving the plant if you cover it with a basket and bury it under several inches of leaves or burlap. Hopefully, it's also in a protected area of your garden. Or, as you suggested, you could buy a new plant in the spring.
I would take it in and try to save it and replace it next spring if it fails to come through. I hate to waste a plant.
Q: I helped my father dig up two wheelbarrows' worth of four o'clocks a few weeks ago. Some bulbs are 40 years old and as big as basketballs. I think you may be mistaken about planting bulbs now in the fall. Or perhaps your advice is not true for all bulbs? We have been planting things for centuries in my family.
A: The column was specifically talking about planting spring bulbs. Four o'clocks fall into a group of bulbs, tubers and corms (like tuberous begonias, caladiums, tuberose and most glads) that are treated as "tender" in our zone. They are not winter-hardy and must be dug up and stored each fall and replanted in the spring. We will be talking more about this class of plants later in the month.
Q: I brought my 3-year-old hibiscus in the house. The plant is approximately 51âÑ2 to 61âÑ2 feet tall. It needs to be pruned, but the plant is still loaded with buds. When do I prune?
A: Any pruning you do at any time will sacrifice flowers and will continue to sacrifice flowers for a few months to come. Prune very early in the spring, and, in the meantime, keep the plant indoors in the brightest, sunniest place in the house and enjoy the flowers.
This week's dirt
Time to put your garden tools away for the year. Wash off the dirt, and clean and oil metal parts. It's always nicer to start with clean tools next spring.
Drain the outside faucets. Disconnect and drain the hose, and coil and tie it neatly. But before you do this, give all of your new plantings a last drink. Then detach the nozzle sprayer. Plan to use winter downtime this year to clean nozzles and replace worn washers. If you have self-draining faucets, you won't need to drain them, but be sure to detach the hose. If you don't detach the hose, the self-draining faucet won't drain properly, and both the hose and the faucet can freeze and burst.
Start a list of tools you might need to buy or replace by next spring. Watch for sales as merchants put away their garden centers for the winter.
Place any moisture-sensitive bags of seed, fertilizers and insecticides in a dry place, particularly if they have been opened. At least get them off the damp floor and up on a pallet for the winter.
One more chore: Find the snow shovel!
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North Shore Gardener by Barbara Barger of Beverly is a regular feature of Wednesday's Lifestyles section. Reach Barbara by e-mail at nsgardener@comcast.net or write to her c/o Salem News, 32 Dunham Road, Beverly, MA 01915. Previous North Shore Gardener columns can be found at www.nsgardener.com.
