Tips from master gardener Toby Bost on how to create and keep a beautiful garden.
March Lawn and Garden
1. Apply a slow-release fertilizer to wake up tall fescue/bluegrass lawns in the mountain and piedmont regions. Applying nitrogen to cool season lawns during the mid- February to March window is an important first step for the coming season. Slow-release fertilizer is preferred over a chemical product, such as 10-10-10, because of the residual greening effect. Though seeding cool season grasses in fall is best, March seeded lawns can give satisfactory results if given more irrigation during the summer months. Wheat straw is not necessary when overseeding existing lawns, except where soil erosion may occur.
2. There are several ways you can reduce or eliminate crabgrass. Some gardeners may choose to use pre-emergent herbicides. Applications of these products should be made before you see crabgrass seedlings. Summer weeds begin germinating in March, often between the flowering of forsythia and dogwoods, and continue through the autumn frost. While pre-emergent herbicides can be very helpful, mowing turfgrass at the correct height reduces crabgrass infestations significantly. This means you may need to raise the mowing deck. Always aim for a dense, healthy lawn to eliminate weeds.
3. Now is the time to research irrigation systems. Many areas of North Carolina were in a moderate to severe drought last year. An irrigation contractor can advise you on all the latest technology. For gardeners growing edibles, micro-irrigation such as drip, T-tape or spray stakes, may prove to be extremely valuable for successful gardening.
4. Cut back ornamental grasses, as new shoots are visible. New shoots come up at their bases in late winter when the soil begins to warm. Trim and groom liriope beds and other groundcover plantings. Remove winter weeds by hand and mulch beds after they are cleaned.
5. Prune spring flowering shrubs after they bloom. Continue pruning evergreen hedges and deciduous shrubs that are summer flowering types, such as roses, buddleias and pee gee hydrangeas.
6. Begin pruning fruit trees, blueberry bushes, grapevines, and brambles as buds begin to swell, but prior to leaf growth. Construct trellises as needed to support vines and caneberries. Velcro tape and nylon cable ties are useful in accomplishing this task. New, wood-treated posts should be set in gravel or concrete.
7. Plan your spring landscaping projects. Walkways, tool sheds, compost bins, raised beds, and retaining walls can be upgraded or constructed while the days are comfortable for outdoor work. Consult a landscape contractor or landscape architect for design ideas and new hardscaping materials.
8. Lumber containing new wood treatments approved by the EPA is available at building supply stores. Wood treatments are necessary to avoid destruction from soil inhabiting fungi and termites. ProWood Micro CA (not CCA) and WeatherShield™ wood materials are commercially available at the big box stores. These wood treatments do not contain arsenic and are copper based. Look for display tags with the acronyms CA and ACQ designating the chemical process. Alternatives to wood treatments include using recycled plastic materials, and composite or untreated lumber.
9. The planting season continues for most garden plants. Take advantage of the cooler weather for planting trees so they have time to establish their roots before hot weather. Always loosen the root ball of container grown plants to free up the roots and encourage new root development. Prepare a wide planting hole for single specimens and a bed for multiple plants. Adding four inches or more of topsoil to a bed with poor drainage may make for better plant establishment. Consider employing French drains for beds of tea roses and herb gardens.
10. Parts of the state can begin sowing vegetable seeds in outdoor gardens. The soil may still be too cold in the mountain region, but coastal and piedmont gardeners can plant garden peas, onions, leeks, potatoes, cabbage and similar cole crops. The Cooperative Extension Agency offers a Vegetable Planting Guide for specific information on variety selection, planting depth, and seed spacing.
11. Start seeds early by retrofitting a raised bed garden into a mini-greenhouse. Bend conduit or PVC pipe to create a hoop house cover. Row covers and clear polyethylene offer the perfect glazing for your project. Remember to provide ventilation on warm days when using clear plastic coverings. Elevated beds sited on an east exposure warm up sooner.
12. Create your own soil mixes for seed and container growing. Use the mix for transplanting woody plants and constructing raised bed gardens. Though recipes vary, most contain equal parts of sand, topsoil and screened leaf compost (or sphagnum peatmoss). Nurseries use pine bark soil conditioner and sand at a 90:10 ratio. The mix (called substrate or media) recommended by Square Foot gardeners is equal parts vermiculite, peatmoss, and organic compost. Play around with soil mixing until you find one that serves your purposes and budget.
13. Start warm-season vegetable and herb seedlings in a sunny window equipped with a bank of florescent lights. Use a timer to operate the lights for 16 hours each day. Position them 5 to 8 inches above the seed-starting flats. Monitor soil moisture daily, and allow 6 weeks or more for the plants to develop several true leaves before moving them outdoors.
14. The N.C. Division of Forestry offers bareroot tree seedlings in environmental packages for reforestation and conservation purposes. Lists of available species can be found here (PDF). The plants are economically priced and delivered to county offices for pickup. Also, garden plants are sold through Cooperative Extension Service spring sales for the benefit of 4-H and Master Gardener programs.
15. Creating a new flowerbed is simple. Use a garden hose to lay out the perimeter of the bed and shape in curvilinear form. Use utility spray paint along the hose line. For rectangular beds, plastic surveyor’s tape and wooden stakes work well. Double digging may be necessary with compacted soil or when planting roses. Otherwise, remove the sod and rototill the soil to thoroughly aerate the bed. Test the soil and add nutrients where deficient. Compost or commercial bagged manure can be raked into the top few inches of bed once the tilling is complete.
16. Prune rose bushes in March. Most of the frigid weather has passed and roses will benefit from an annual pruning to remove weak and diseased canes. While Knock Out™ roses require less severe pruning they should be pruned occasionally with thinning cuts to allow light into the shrub’s interior. Lop them back to keep their height down when needed. NOTE: there is a new disease affecting Knockout roses called rose rosette. Diseased roses must be removed from your landscape beds! Visual symptoms include witches broom, reddish new growth and hyperthorniness. Chemical sprays will not cure the disease.
17. The last frost-free day may not be Good Friday this year. Because the Easter holiday is earlier than usual, do not go by this traditional marker. Watch your local forecast and refer to this handy planting guide from The Old Farmer’s Almanac.
For more than 30 years, Toby Bost has been a resource to North Carolina gardeners and growers as an agricultural extension agent, a trainer for master gardeners, and an author. His books include The Successful Gardener Guide: North Carolina, North Carolina Gardener’s Guide, and The Carolina Gardener’s Guide. He can be reached through Our State magazine at firstname.lastname@example.org
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