After a hard winter, most of us are looking forward to spring. Spring has its challenges as well as its beauty. It’s time to get your landscaping plans for the growing season finalized. Tour the landscape to determine maintenance that needs to be done to repair winter damage and consider what could be done to improve your site.
Look for products using recovered organic materials and biobased alternatives to traditional chemical fertilizers, herbicides and pesticides.
Plan for the Future
Determine your landscape needs for the next growing season. Some common topics are:
- Is there winter damage that will require replacement of existing plants?
- Review what worked and what didn’t last growing season and consider changes that need to be made in the maintenance plan for the upcoming growing season.
- If any improvements are planned for your landscape, now is the time to discuss them with your landscape professional so that the work can be planned and scheduled. Landscape companies tend to be very busy during the growing season and have time to plan when plants are dormant.
While touring your site, assess the condition of your lawn and consider alternative solutions for problem areas. Many common lawn problems such as weeds, thin grass, and bare spots occur because of poor soil structure, lack of nutrients or compacted soil. Lifting a patch of turf and examining the soil will often provide clues about soil condition. Other turf problems are the result of planting grass in the wrong location. Grass rarely thrives in shady areas and high traffic locations. Consider shade-loving ground covers and paths instead.
Lawn Care Suggestions
- Leave grass clippings on lawn to supply nitrogen.
- Use natural fertilizers such as compost, corn gluten meal (a natural “weed and feed”) and meal from fish, kelp, or legumes to supply nitrogen. Look for products using recovered organic materials and biobased alternatives to traditional chemical fertilizers, herbicides and pesticides.
- Avoid chemical fertilizers – they harm beneficial organisms and earthworms.
- Consider planting clover in your lawn to supply nitrogen.
- Aerate established lawns if your soil is compacted. Core aeration makes holes and drops soil plugs back onto lawn.
- Add compost and over-seed after aeration to rejuvenate your lawn.
- Mow high (3 to 3½”) to shade out weeds. Lawns with taller grass have fewer weeds. Never cut more than 1/3 of the grass blade at a time. Many lawn mowers allow raising the bed of the mower.
- If you water your lawn, water deeply (to 6” down) and infrequently to encourage deep grass roots. To determine how long to water, place a glass on the lawn and monitor how long it takes to fill it 6”. Except under extreme drought conditions, it is not necessary to mow or water in hot, dry weather when grass goes dormant. Dormant grass will recover in the fall.
- Remove weeds in the spring when plant root reserves are low. Use a dandelion digger or pronged grabber tool to pull tap-rooted weeds such as dandelions, thistles, and burdock. Rake or pull creeping charlie.
- Apply corn gluten meal in the early spring to prevent weed seeds from taking root on established lawns. This product is most effective on crabgrass seedlings, but has also shown promise with other seedlings, such as dandelion. If crabgrass persists on your lawn and sets seed, apply corn gluten meal again in the fall. Use corn gluten meal annually to diminish the number of weeds in your lawn over time. This product is also an organic source of nitrogen.
- Give weeds stiff competition.
- Select the grass seed mix that is appropriate for the amount of light your lawn receives.
- Over seed your lawn in the fall. Grass is a cool weather crop; starting more grass plants in the fall will give weed seeds more competition next summer.
- Sprinkle grass seed on bare spots after weeding.
Tolerate Plant Diversity
Lawns will always have some weeds and some insects. Even heavily treated lawns have weeds. Weed seeds blow in from other yards and are carried by feet and dropped by birds. Avoid pesticides and tolerate a few weeds for the greater good of the environment and your health.
• Sharpen mower blades. Set to 3-3 ½”. Tune up mower.
• Begin mowing, leaving grass clippings on lawn. Edge paths.
• To stop weed seedlings from taking root, apply corn gluten meal at the rate of 12 lbs. /1000 sq. ft. Spread the product just as weed seeds are germinating. A rule of thumb is to apply corn gluten meal in April when forsythia blooms. This is usually the time when the grass is beginning to turn green, but before trees have begun to leaf out.
- Aerate, and if thatch is a problem use a power rake.
Late MayEarly June
- If you want to make two nitrogen applications this year, apply the first one now. Apply no more than 2-3 lbs nitrogen/1000 sq. ft. per year on sunny lawns or 1-1.5 lbs nitrogen/1000 sq. ft. on shady lawns. Never apply more than 1 lb nitrogen/1000 sq. ft. at one time. Use natural sources, such as compost, manure, fish meal or vegetable meal fertilizer.
• Don’t apply nitrogen now if you used corn gluten meal on weeds. Corn gluten contains 1 lb. of nitrogen per application.
April - June
• Dig or rake creeping charlie, dig dandelions, burdock, thistle, and other perennial weeds. This is the most effective time of year to weed since root reserves are at their lowest in the spring.
Spring is an excellent time to rejuvenate groundcovers such as Ivy, Vinca and Wintercreeper. In addition to pruning, this is an excellent time to remove weeds, debris and add compost to the beds. Rejuvenation pruning should be done every 2-3 years.
Pruning will encourage new growth on many ground covers by forcing buds to break along the stem or at the crown of the plant. This can easily be achieved in various ways, depending on the size of the area. Hand pruners or a mower with a sharp blade set at its highest mowing height will work well to prune ground covers. Pruning will not only improve rejuvenation, but also maintain size control of such ground covers as bugleweed (Ajuga reptans) and wintercreeper (Euonymous fortunei). A second flowering on such ground covers as cottage pinks (Dianthus gratianopolitanus) can be induced by cutting back plants after flowering. Plants that have long stems should be cut back about halfway to encourage branching. Insect problems and diseases can be deterred by pruning to increase air circulation, pruning out dead or diseased plant parts, and by enabling sunlight to reach the center of the plant.
How much a plant should be cut back depends on the type of plant, its growth cycle, and the purpose of pruning. For example, some ground covers, such as Japanese spurge, (Pachysandra terminalis) should be pruned just after new growth has emerged in the spring to encourage a compact, bushy habit. Others should be cut back after blooming to promote a second bloom, as in the case of leadwort (Ceratostigma plumbaginoides) and candytuft (Iberis sempervirens).
Ornamental grasses should be cut back to the ground each spring to encourage light and moisture to reach the new growth at the base of the plant. Do not cut them back in the winter as the old foliage acts as insulation for the root system and provides valuable winter interest. Choice of tools will depend on the size of the plant and how many plants require pruning. A hand pruner may be fine for a few plants, but for a mass of plants, electric hedge trimmers, a string trimmer or a hedge pruner is recommended. Burning is also an option for large areas and will require a permit from your municipality.
Planting beds need spring maintenance. If mulched, the mulch needs to be raked and cleaned of debris. Grass, weeds and plants that have taken up residence in unexpected places in the beds need to be removed. A layer of compost or organic fertilizer should be added to the soil before replacing the mulch. If mulch has composted to less that 2 inches, additional mulch should be added to the beds to increase the depth to 2 inches. Mulch should not be mounded around the base of plants and is not recommended where you will be planting annuals.
When to Plant
Trees and shrubs can be planted as soon as the soil thaws. Do not plant or till the soil when the soil is water logged from heavy rains. Not only is the risk of personal injury greater, the soil structure can be damaged and the plants will have a lower chance of success. Tilling water logged soil can create hardpan, a dense layer of soil that restricts root growth and the movement of moisture, air and beneficial organisms through the soil.
Herbaceous plants and seeds can be planted after the last frost date in spring (see chart below). Seeds are less expensive to buy, however, in northern climates, seeds are often started indoors then hardened off and planted outdoors after the last frost date. This is done so that the plants can have the greatest impact during the growing season. Many gardeners buy seedlings – small plants that are ready to plant in the landscape.
Annuals vs. Perennials
Annuals are plants whose life cycle is one growing season. Many vegetables are annuals as well as bedding plants (available in flats or 4 inch pots). In northern climates many plants that would be grown as perennials in the south are grown as annuals in the north because they will not survive the winter. Hardiness zones apply to all plants, including trees and shrubs. Annuals offer continuous bloom and color throughout the season
Perennials are plants that are expected to have a life cycle of more than one year. Some perennials have a longer expected life cycle than others. Biennials such as Digitalis (Foxglove) have a two year life cycle. Others such as Gallardia (Blanket Flower) and Lobelia Cardinalis (Cardinal Flower) are short lived. Peony on the other hand will live for more than 20 years. Perennials are usually sold in one gallon containers or larger. Most perennials bloom from 2 – 6 weeks during a growing season, so selecting plants that bloom at different times will be necessary to maintain color in the landscape over the growing season.
When reviewing perennials, it’s important to determine if the plant you are considering is rated as a perennial in your hardiness zone. At a nursery, you can look at the tags. Online, this information is usually provided. Below are sites I’ve found useful.