The last week of September is a good time to check all trees and shrubs for webbing that might signal tent caterpillars.
Pick up fallen apples and other tree fruit so they don’t begin to rot and attract garden pests. Continue to harvest vegetables, including green tomatoes, before the first frost arrives. You can renew your raspberry and strawberry plants by cutting off the runners or side shoots and replanting the offspring into amended soil now.
Question. I read we were not supposed to prune roses in the late summer or fall as this stimulates them and the idea is to get them to go dormant before winter. I still have lots of roses in flower. Is it OK to keep harvesting them with long stems or is this a form of pruning? R.F., Tacoma
Answer. No worries, gather thee roses whenever they are in bloom. In Western Washington, our winters are considered mild and most roses do just fine if you pick or prune them in the fall, winter or spring.
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Stop fertilizing roses and perennials this month to slow any new growth but enjoy a happy harvest of late-season blooms from whatever is flowering this month.
Q. I planted dahlias for the first time this summer. They did great. Now what do I do so that they come back next year? D.M. Puyallup
A. There are hundreds of different dahlia varieties out there, but if you planted tuberous dahlias, you have several choices for care this winter.
The safest option is to wait until the tops begin to turn yellow, then cut the stems to the ground and uproot the bulb-like tuber. Set it indoors to dry a bit and then brush off the damp soil and store the potato-like root in a paper bag in a cool, dry spot. You then can replant this tuber in late spring for another summer of blooms.
If you are a gambling gardener, have raised beds or quick draining soil, you have the option of leaving your dahlia tubers in the ground over the winter. To keep the rain and cold from rotting your dahlia roots, you will need to cover the soil with a tarp or a layer of sword fern fronds to keep out the moisture.
Dahlias overwintered outdoors might be slow to emerge from the ground in the spring so be patient — and watch for slugs that love the tender new shoots.
Q. How long can I harvest herb plants from my garden? Specifically, I have some mint growing in a pot and with winter coming I need to know how long I can keep cutting leaves from this plant. I don’t want to prune it too late into the winter and kill it off, but I have become fond of mint leaves added to my tea and would like to enjoy fresh mint for as long as possible. H.L., Black Diamond
A. Go ahead and get snippy and enjoy the harvest and herbal renewal.
Mint is one of the most reliable herbs to grow in our area and as long as you see new growth you can continue to harvest the top one third of the plant. You can even grow mint indoors for the winter months if you have room near a sunny window.
Mint plants can easily be started from cuttings in the spring. Just snip off a pencil-length stem of mint and place it in a glass of water. Roots will form on the stem and the new plant can be transplanted into potting soil. Just be aware that mint steals real estate from nearby plants, so growing this herb in a container is a good way to keep it well behaved.
You might want to expand your minty palette by growing chocolate mint, apple mint and other mint varieties offered by local nurseries in the herb section — or by rooting plants from the fresh mint sold in the produce section of the grocery store.