Dear Carol: I have enclosed a sample of an invasive plant that has taken over one of my perennial beds. The threadlike roots make it impossible to remove by hand, even with a large trowel dug in deep.
It begins early, small dark and green, enlarges all season and some individual plants are a foot square or more. Fortunately it stays low but it becomes much more prominent and unattractive each passing month. I've had this problem for about three years. How do I get rid of it? -- S.J., Cazenovia.
Dear S.J.: There are several annual weeds that resemble the dried sample you sent. Spotted spurge, prostrate knotweed and portulaca are in this group of mat-forming weeds that grow from seed every year and die in the fall. The plants flower young and produce lots of seed. The flowers are generally tiny and inconspicuous. Spotted spurge can flower when the plants are two weeks old.
The key to getting rid of annual weeds is the regular use of a hoe early in the season when the plants are still immature. Once the seeds mature, they fall to the ground and establish a "seed bank" in the soil. These seeds can remain viable for decades, with many germinating every year and creating a long-lasting weed problem. The old saying is "One year's seeding means seven years' weeding."
Hoeing should not be heavy work. It is much faster than hand weeding, and you can work standing up. It's important to find a style of hoe you like; there are dozens. A triangular Warren hoe is good for getting close to the base of perennials. You don't want a "grub" type of hoe that is used to chop at heavy soil. Most hoes designed for weeding have a sharpened blade that is worked parallel to and just below the soil surface. The idea is to slice the surface of the soil, uprooting tiny weeds and severing the tops of bigger ones. Hoeing too deeply will harm the roots of the plants you are trying to grow.
The good thing about annual weeds is that typically you do not have to dig them out completely. They dry up and die when uprooted or severed and will not resprout from the roots left in the ground. Occasionally, if it rains soon after you've finished hoeing, portulaca, which is quite succulent, will replant itself in the loose soil and start growing again. But don't let that possibility deter you from hoeing.
Perennial weeds, bindweed, thistles, healall, veronica and so on, could not care less about being hoed. These weeds have huge root systems with plenty of stored energy and dormant buds. They resprout from the tiniest piece of root left in the ground and have to be dug out completely. Annual weeds, although abundant and annoying, are not in the same league as the perennials.
Carol T. Bradford, of Syracuse, has been gardening in Central New York for more than 25 years. Send questions in care of Home & Garden, The Post-Standard, P.O. Box 4915, Syracuse, NY 13221, by fax to 470-2111 or by email to firstname.lastname@example.org. Letters might be edited for space and clarity.