Weeds can quickly overrun any planting and turn an enthusiastic gardener into a frustrated one. The most critical time to weed is just after planting, particularly in spring. Keep a close eye on areas with newly planted ground covers until the plants are dense enough to shade the ground and choke out weeds. And make sure that the planting site is weed-free before setting in any plants.
Walk through your garden or newly planted area about once a week, taking along a bag and weeding tool. Place all pulled weeds in the bag; if left on the ground they could re-root or spread seeds, causing additional problems.
Scotts Crabgrass Preventer kills weed seeds as they germinate. Spread the Halts just before the time you expect most weed seeds to germinate—in the spring everywhere, and again in the fall in mild-winter areas. Once spread, don’t dig or disturb the soil. Weeds can sprout where the soil has been disturbed.
In established plantings, use garden grass killer to control grassy weeds without harming the ground cover. Apply any chemical with care, following the instructions on the label. You may also spot-treat with grass killer, being careful to spray only the weeds without wetting the groundcover.
Mulching newly planted beds will help stave off the weed population. Mulches should be applied only after the soil has warmed in spring, A generous quantity will stop many of the most troublesome annual weeds and make it easier to pull ones that do sprout—2 to 3 inches will prevent most weeds from growing. Some of the better mulches are fir bark and tree leaves that have been ground up. There are many others, the availability of which depends on the region. Cover the bare soil between plants, letting the ground cover grow onto the mulch.
Besides preventing weeds from growing, some mulches improve the soil and add nutrients as they decompose. They also conserve moisture, an important consideration where water is in short supply and when young, shallow-rooted plants are just getting started. Finally, they help regulate soil temperature, creating a more favorable root environment.
Shredded hardwood, pine, or fir bark makes an excellent mulch that is easy to apply and very attractive. It also adds valuable organic matter to the soil.
Shredded tree leaves
These are an excellent source of humus. They rot rapidly and are high in nutrients. They are attractive, with a natural appearance. Some leaves can be spread as a mulch without shredding. Thin leaves that mat down, like maple leaves, should be shredded before using as a mulch.
In many areas, pine needles will need to be replenished yearly. However, they won’t mat down and can take some traffic.
Where they are available in large quantities, ground corncobs make an excellent mulch and improve the soil structure.
Hay and straw
Although unattractive, hay and straw can be used for mulching purposes. Repeated use builds up a reserve of available nutrients in the soil that will last for years. Hay is particularly rich in nutrients. Hay may contain weed seeds, and straw probably contains grass seeds as well as weed seeds. Test-germinate a sample to find out.
Grass clippings from your lawn make a fine-textured, attractive mulch that turns from green to bright yellow as it ages. Don’t use clippings if they might contain herbicides. Spread them less than an inch deep at any one mowing to allow them to dry quickly, then add more depth at each mowing. If spread too deeply while green, they will form a cardboard-like mat that is difficult to wet once it dries out. Dry clippings blow readily in the wind. Don’t use them if you live in a windy location.