SPRING GARDENING TIPS
Growing Annuals from Seed
Growing annuals like zinnias, marigolds, and tomatoes from seed is easy and economical. The exact time to start seeds varies with the plant and with your location. In general, it's about six weeks before the date of the average last frost in your area. Seed catalogs and packages usually list the number of weeks needed when starting seeds indoors.
Use a potting mix specially formulated to start seeds; you can find such mixes at almost any garden center or hardware store. The mixes are sterile, provide the drainage that seedlings need, and are sometimes enriched with fertilizer. Fill peat pots or other seed-starting containers with the mix and thoroughly moisten it. Then sow your seeds of choice following the directions on the packet.
Place the containers on a tray in a very sunny window or under a grow light. Never allow them to dry out. As soon as the seedlings develop four leaves, use scissors to thin out your seedlings, leaving just the healthiest looking ones.After all danger of frost has passed, place the trays of seedlings outdoors in a sheltered place for several days, gradually lengthening the time they are exposed to the sun and wind to prevent scorching the leaves, before transplanting them into the garden.
A little TLC for your perennials
Herbaceous perennials and grasses, a group of diverse and reliable plants that return to the garden year after year, can greatly benefit from a little extra attention in the spring. Here are some tasks that will help your plants get off to a healthy start.
- Remove winter mulch from around the crowns of perennials.
- Cut back any parts of the plant that were left up for winter interest, such as flower stalks and seed heads.
- For evergreen perennials, remove any dead leaves.
- When new growth is about three to four inches tall, dividing and transplanting may be done. For spring-flowering plants, wait till they are finished blooming.
- Begin placing stakes to support the growth of tall or fragile perennials.
Pruning early-blooming shrubs
Shrubs that bloom early in the year, such as forsythia, form their flower buds the previous year. In the rush of the spring season, there are always so many chores to do it's easy to forget that these early flowering shrubs need pruning immediately after bloom. If you wait too long before getting around to it, you'll cut off next year's flower buds. And if you don't prune at all, these strong growers will quickly turn into giant tangles.
As soon as the last flowers fade, use a pruning saw to cut off one-fourth to one-third of the biggest, oldest stems at ground level. Use pruning shears to shorten all of the stems to two or three feet from the ground. If you wish to greatly limit the shrub's size, you can cut the branches as far back as six inches from the ground. By the end of the growing season, new branches will have formed. These will arch gracefully from the center and will be covered with new flower buds for next year's spring show.
SUMMER GARDENING TIPS
WATER WISE TIPS
Whether it will be a droughty summer or not, lawns and gardens almost always require some supplemental watering. However, there are a few things gardeners can do to reduce the frequency of watering and amount of water needed.
- Use drought-tolerant plants.
Many annuals, perennials, ornamental grasses, and shrubs do well with little watering. Check with your local garden centers or Extension service for lists of these plants.
- Reduce or eliminate use of chemical fertilizers.
These promote lush growth, which requires more water to support. Instead, use compost and mycorrhizae. Compost adds nutrients very gradually and improves the soil’s ability to hold water. Mycorrhizae are tiny, beneficial microorganisms that actually help plants take up water and nutrients.These are available from garden centers and mail-order companies in liquid or powder form.
- Apply plenty of mulch.
Don’t allow it to touch tree trunks or plant stems, but apply it deeply—up to six inches—in the blank spaces between plants, where the sun would otherwise hit the ground and dry it out. Around trees, angle the slope of the mulch so that water runs toward the tree.
- Install a drip irrigation system or soaker hoses.
Because drip irrigation systems and soaker hoses deliver water directly to the root zone, they will do more good and use far less water than sprinklers. If you do use sprinklers, consider installing a timer to minimize waste.
- Lose the lawn.
Consider converting some of the lawn to garden beds or plant a drought tolerant native turf grass or groundcover that is not dependent upon weekly (or even more frequent) irrigation. In the West, buffalo grass is a good replacement for conventional turf lawns.
Ornamental grasses are tough, low-maintenance plants that provide four seasons of interest in the garden. These grasses emerge in late spring, at which time they are very effective in camouflaging the foliage of spent daffodils and other bulbs. They look full and lush all summer long. Most ornamental grasses are late bloomers, some waiting until October to produce their unique spiky flowers. After they have been hit by frost, their green foliage turns lovely, tawny shades that contrast with the reds of turning leaves and the deep greens of evergreens.
One of the few maintenance chores with ornamental grasses is a yearly shearing back of the dried foliage in early spring. Beyond that, these plants require little care and most are pest and disease free. Just be sure to site them in a sunny spot because most require at least six hours of sunshine.
Some good grasses to try are:
- Big bluestem (Adropogon gerardii)
- Fountain grass (Pennisetum alopecuroides)
- Prairie dropseed (Sporobolus heterolepis)
- Switch grass (Panicum virgatum)
- Feather reed grass (Calamagrostis x acutiflora)
- River oats (Chasmanthium latifolium)
When you combine annuals in a container, it intensifies their effect. A container also allows you to dress up places where plants don’t grow such as patios and balconies. Whether you have a sunny or shady spot, there are annuals to help add sparkle.
For shady places in your garden, choose annuals that prefer to be cool and shady. Among these are coleus, fuchsia, impatiens, begonias, and caladiums. The choices for sun are almost numberless. Geraniums and petunias are classic sun-loving container plants, and are available in a wide array of colors.
To keep your annuals blooming their best all season long, make sure to water often enough to avoid wilting and deadhead spent flowers. An occasional application of slow-release organic fertilizer will help, too.
FALL GARDENING TIPS
If deer are a problem in your area, this autumn you may want to plant bulbs that deer don’t find so tasty. These include daffodils, alliums, and lycoris for bulbs.
There are hundreds of wonderful daffodil varieties to choose from. One great naturalizer that is also outstandingly attractive is‘Ceylon’, which grows 15 inches tall, and produces bright golden petals around an orange cup. Among white varieties, graceful ‘Thalia’ is hard to beat. Late-bloomers like ‘Hawera’, an eight-inch tall daffodil with diminutive lemon blossoms, and ‘Actaea’, a daffodil with linen-white flowers punctuated by red and yellow coronas, can fill the garden with grace and fragrance.
Alliums—also known as flowering onions—are perennials that come in all sizes, mostly with clusters of starlike flowers in shades of pink and purple. One of the most spectacular is the giant allium,Allium giganteum (USDA Hardiness Zones 6-10, AHS Heat Zones 9-5), which produces a ball of bright purple flowers, six inches across, on a stem that can reach four feet. Equally impressive is Schubert’s allium, Allium schubertii (Zones 4-10, 10-1), a spidery purple flower ball reaching up to 12 inches across on a 15-inch stem.
Lycoris are hardy members of the Amaryllis family that bloom in late summer and early fall. Naked ladies, Lycoris squamigera(Zones 6-11, 12-6), so called because their blooms appear long after the leaves have withered away, bear fragrant, pink flowers on strong, two-foot-tall stems in late July and August.
Late-blooming Asters
While many summer flowers have faded away, asters are one group of plants that blooms late in the garden’s final season. The aster parade begins in mid-summer and continues until hard frost, with the great majority blooming in August to September.
Aster carolinianus (Zones 4-8, 8-1) is a late bloomer, unique to the genus. In mid-October, this gray-green leaved aster, native to the southeast, will scramble to the top of a six-foot post or trellis and burst into rose pink flowers that turn lilac with age.
Aster ‘October Skies’, another late-blooming native, bears colors that mirror the clear autumn skies in October. Unlike many asters, ‘October Skies’ is short and bushy—growing only about two feet tall. Taller, darker, and later-blooming is ‘Fanny’s Aster’, which matures into a four-foot shrub stitched with dark purple flowers that open in October and remain into November.
Fall Color from Shrubs
If you’re looking for something to add brilliant fall color at or near ground level in your garden, try the native shrubs Virginia sweetspire, Itea virginica (Zones 6-9, 10-7) and oakleaf hydrangea,Hydrangea quercifolia (Zones 5-9, 9-5). Both retain their colorful foliage into winter, even when planted in the shade.
The big leathery leaves of oakleaf hydrangea begin turning in October from summer’s dark green to myriad tints from bright pink to deep maroon. Oakleaf hydrangeas grow into wider-than-tall colonies with the potential to reach 10 feet in height, but usually topping out at six to eight feet. Their relatively high stature allows them to show off their attractive tawny-colored bark, which can be somewhat hidden along the plant’s denser sections by the oaklike leaves.
Virginia sweetspire is shorter, growing three to five feet tall. It grows into a broad mound of arching branches, a habit that makes it useful as a large-scale ground cover. In late spring to early summer, long, white flowers—each composed of hundreds of tiny white bells—appear at the end of the branches. But it is in fall that this shrub is at its best. Some particularly colorful varieties include ‘Henry’s Garnet’, which takes on the deep jewel tones of a garnet; ‘Saturnalia’, which blends ruby tones with garnets; and ‘Little Henry’, a lower growing form that peaks at about two feet and bears glowing red leaves.
Improving Your Soil With Autumn’s Bounty
At this time of the year, fallen leaves are everywhere—and they’re a great, inexpensive source of organic material for enriching your garden soil. Leaves should be shredded to help them break down in the soil more quickly. If you don’t have a leaf shredder, rake leaves into long, low piles and then run your lawn mower back and forth over them. Some communities even offer composted leaves to residents free of charge, so check with your local government offices to see if you can take advantage of that wonderful resource.
Japanese Anemones of Note
Ongoing evaluations of Japanese anemone at the Chicago Botanic Garden (CBG) have yielded several promising cultivars. Grown for their mid-autumn blooms, anemones are ideal for borders, woodland, and rock gardens.
The CBG has tested seven cultivars of Anemone hupehensis and A. hupehensis japonica along with ten cultivars of A. x hybrida (A. hupehensis x A. vitifolia). “The Avant Gardener” newsletter reports that three cultivars of A. x hybrida “received top marks”: yellow-centered white ‘Andrea Atkinson’, light pink ‘Max Vogel’, and pink ‘Serenade’.
Of Anemone hupehensis and A. hupehensis japonica species, four cultivars stood out above the rest: rose pink A. hupehensis ‘Splendens’, double pink A. hupehensis japonica ‘Prinz Heinrich’, light purple A. hybrida ‘September Charm’, and pale pink A. hybrida ‘Robustissima’.
Fall is the perfect season to enjoy anemones and it is also the season to plant them. Japanese anemones should be planted two inches deep in moist, fertile, humus-rich soil in sun or partial shade. The plants, once established, may sometimes spread by easily removable rhizomes.
WINTER GARDENING TIPS
Winter is a good time to prune deciduous trees. Once the foliage has dropped, it’s easier to get a look at the branching structure and spot any potential problems. Richard Eaton, an arborist with The Care of Trees, an AHS partner and a national tree care company, shares the following tips for pruning small or recently planted deciduous trees:
- Prune out any diseased or broken limbs.
- Remove branches that cross over one another.
- Remove branches that go against the flow of the tree’s natural habit (i.e. upward pointing branches on a weeping tree).
- Avoid pruning branches completely flush with the trunk or major limbs; make cuts slightly above the junction point, leaving the branch “collar” intact.
- Don’t use wound sealants; trees have a natural ability to heal themselves.
- Try not to disrupt the natural architecture of the tree.
- Be conservative; cut only branches you are confident need to be removed.
- For safety, use tools that allow you to reach up into the canopy, such as pole pruner, rather than climbing up on a ladder. If you need a ladder, says Eaton, it’s probably time to call a certified arborist.
Cutting Back Ornamental Grasses
Ornamental grasses such as maiden grass (Miscanthusspp), river oats (Chasmanthium latifolium), and fountain grass (Pennisetum spp.) often remain attractive in winter, even though they are completely dormant. In winter, their foliage turns from summer greens to shades of wheat and almond. They are especially striking when contrasted with evergreens.
There are two rules regarding when to cut back ornamental grasses. The first is that it is up to the gardener to decide when they are no longer attractive. Snow, sleet, and freezing rain can ruin their effect. Once this happens, the time has come to cut them back to a few inches above the ground.
The second rule for cutting back grasses is that the annual clipping must occur before new growth starts in the spring. And it's a good idea to trim them before plants around them start to awaken so as to avoid trampling the tender shoots of emerging bulbs and perennials.
Forcing branches for winter bouquets
The flowers of some shrubs and trees can be "forced," induced to bloom, indoors while the winter weather outside continues. Some of the easiest to force include pussy willows (Salix spp), flowering quince (Chaenomeles speciosa), and forsythias (Forsythia spp.).
Among the pussy willows, the Japanese pussy willow (Salix chaenomeloides), a small tree that reaches about 18 feet, has three-inch long, fuzzy pink flowers known as “catkins”. The black pussy willow grows to 10 feet and has purple-black catkins.Flowering quince is a six to 10 foot shrub with flowers that are usually orange-red. There are also pink and white flowering forms. Forsythias come in many shapes and shades of yellow. One of the earliest to bloom is called early forsythia (Forsythia ovata), which blooms from March to April.
To force the branches of any one of these shrubs, cut them in January or February. Submerge the branches in tepid water overnight. The next day, place the branches upright in a container of water, making sure to cut off any buds from the parts of the stem below water in the vase. Leave the branches in a cool, dimly-lit room and change the water daily until the buds start to swell. Then, move them to a brightly-lit room and enjoy the colorful display!
Take Stock of Your Garden’s Design in Late Winter
Winter is the best time to take stock of the permanent elements of your landscape--the lawn, paths, and evergreens. As the backbone of your landscape's design, these parts of the garden interact with deciduous plants during the growing season.
If you find that your yard looks well-stocked, but pretty much the same, winter and summer, you may wish to make room for a small shrub or tree to add excitement with spring or summer flowers. Lilacs (Syringa spp), viburnums, and hydrangeas are flowering shrubs that come in many sizes and colors. Stewartias (Stewartiaspp.) and the ‘Forest Pansy’ redbud (Cercis 'Forest Pansy') are excellent small flowering trees. Japanese maples (Acer palmatum) put on a glorious show in spring when the leaves emerge and in fall when they turn a dazzling scarlet.
After the first killing frost, does your garden seem empty or lacking in definition? Then look first to the lawn--it may be that its size outweighs other elements in your yard. If that is the case, consider adding planting beds--a larger one in front of the house, beds around existing trees to link them together, or a bed around the periphery of your lawn. Incorporate plants that provide winter interest into these beds.
If you don’t have any evergreens, plan to add some this coming spring, keeping their ultimate sizes in mind. The choices are almost limitless, but if deer are a problem in your area, some evergreens they don't eat are plum yew (Cephalotaxus spp.) and boxwoods (Buxus spp.).
Wildlife in the Garden
Wildlife adds life and color to a garden that is especially welcome in late winter. Now is the time to take stock of the wildlife-friendly elements already in place in your garden and plan to add more in the next growing season to provide for wildlife throughout the long winter.
Think about adding the sorts of plants that invite wildlife into your garden—generally ones that produce food or shelter. Consider those that go to seed or produce berries at different times to keep edibles at hand throughout the dormant season. Natives such as goldenrods (Solidago spp.) and coneflowers (Echinacea spp.) have evolved in tandem with the birds and small animals of your region. Allow their seedheads to stand over winter.
Thick or thorny shrubs and evergreens are safe places for cover or nesting. And layers of vegetation—stepping down from trees to shrubs to herbaceous ground covers—provide shelter. Be sure to provide a source of water, too. And, most important of all, try not to use synthetic chemical pesticides, which may harm wildlife.