Here's the scoop on popular annuals and perennials
If you're thinking of planting perennials, be sure to look for Zone 4 or lower hardiness, i.e. plants that survive average minimum temperatures of -20 to -30 degrees – that's our climate.
Most perennials hardy in Zone 4 need some winter protection – primarily mulching; most need quite a bit of sun. There are many varieties of perennials, each with many needs, including temperature conditions, planting requirements, resistance or susceptibility to disease or insect invasions, bloom time, feeding requirements and so forth. Not that these are particularly difficult or picky; once you get most of these perennials in the ground, they'll do just fine.
Catalogs from nurseries that offer perennial plants are good study guides, although you may want to look up the same plant in several catalogs to compare data; some catalogs – especially those from nurseries in fairly temperate zones – don't zone plants appropriately. Yes, a Zone 5 plant (able to survive average minimum temperatures of -10 to -20 degrees) might survive Minnesota winters if planted in protected areas and are well-mulched each winter. But you could lose the plant in a very cold winter.
For a permanent reference, get a book on perennials (available for $8 to $100) or the perennial plant booklet published by the Minnesota Landscape and Nursery Association from many nurseries for 50 cents and $1. Use these to learn about plants and to help you plan your garden.
Try to establish a plan that gives you lighter-colored plants in shady areas, perennial blooms all season (possibly by interplanting groups of early-, mid- and late-blooming flowers), plants of appropriate heights (taller one in back, for instance) and mixed foliage textures (such as the large leaf of a tall canna lily near a stand of baby's breath). Choose single color schemes (all whites, or a purple-red combination) or combinations that please you (even orange and pink if you like).
Keep in mind that you'll want to see your plants both from close up (as you walk by, as you weed, as you sit on your garden bench), and from afar (through your dining room window, as you drive up to the garage, or from the deck). Plan focal points – a tree, a statute or bird bath, a fence or an arbor – that draw attention, around which to coordinate your plants.
Take into consideration taller, distant objects as well. You may enjoy that glimpse of the top of the IDS building peeking out between trees, but despise the bumblebee-painted side of the town's water tower. Take advantage of the first, and plant a tree or build a tall structure to screen the second. Perennials
Asters Hardy asters are among the longest-blooming and showiest in the garden, although they don't usually start blooming until late summer and fall. The individual daisy-like blooms are nice for cut flowers, and also supply masses of color as other garden blooms are fading or gone.
Astilbe This plant does well in shade and is a great textural plant in the garden, with tall, fluffy flower wands in colors ranging from white through pale to bright pinks to a rich magenta, and fine ferny foliage that sometimes has a touch of bronze. Combines well with hosta. Heights range from 12 to 36 inches.
Baby's breath (Gypsophila) Any gardener who likes to cut bouquets, fresh or dried, or who likes the look of a lacy cloud in the garden would enjoy growing this easy-care plant. There are single- and double-flower forms, white and pink varieties. There are short (6-inch) to tall (40-inch) varieties.
Chrysanthemums Here's a war-horse in the autumn garden, but be sure to look for varieties that are hardy to Zone 4. Many have been developed by the University of Minnesota; those often have "minn" in their names. The painted and Shasta daisies are forms of chrysanthemums that bloom in summer. Many potted chrysanthemums should be treated as annuals.
Clematis This vine has dozens, maybe hundreds of cultivars, many of which are hardy in our climate. The most obvious is the Jackmanii, with rich, lush purple flowers, but there are varieties in many forms and colors ranging from white to magenta, striped pinks and blue. Flowers can be up to 6 inches wide, and the seed pods are lovely after the blooms are spent. They look nice on a fence, trellis and even growing among the foliage of a climbing rose.
Coneflowers (Echinacea) This native prairie flower, usually purple but also available in white, is a yeoman of the garden. Hardy, reliable, attracts butterflies, nice cut flower. You don't even have to deadhead - leave the stalks in all winter to attract birds to their seeds.
Coralbells (Heuchera) Here's a nice, hardy plant, with ground-hugging (ground-cover) leaves in variegated greens to bronzy-purple with tall wands of delicate blooms in pinks, whites and reds. And it does well just about anywhere - even light shade.
Coreopsis A nice, easy plant that brings a sunny yellow to the garden and cut bouquets. It's available and hardy in several forms, from a mum-like button form to a daisy form (there is one daisy form that's available in pink). It blooms more if you deadhead spent blooms.
Daylilies (Hemerocallis) This is one of the easiest perennials to grow: They take sun or some shade, need little maintenance and thrive under even unfavorable conditions. They also come in hundreds of colors from yellows and oranges to reds, pinks and bi-colors; plus tall, short, medium, ruffled, double or twisted. Delphiniums Ah, the blue spikes of the delphinium - such a charming, elegant flower. Some people call it "challenging" to grow, and it isn't always hardy in Zone 4, but keep on trying, just mulch it well in winter. Several varieties range from 3 feet to occasionally 8 feet tall. There are several blue shades, plus white and pink.
Dianthus Also known as pinks, or tiny carnations, these hardy spring flowers bloom most of the season if spent flowers are cut off. The spicily fragrant plant has flower colors ranging from rose and pink to sharp reds, whites, salmon and yellow. Foliage colors in silvery blue or green add contrast to the garden. Heights range from 6 to 24 inches.
Foxglove (Digitalis) This spiky-blooming biennial plant is a favorite in "English cottage gardens" and freely reseeds if you've got a good stand going. It's tender in Zone 4, but can survive if well-mulched in winter and treated very tenderly in early spring. Flower stalks can grow from 3 to 4 feet tall.
Hosta This shade-loving plant can grow in the sun, but prefers shade, where it's beloved for its foliage. Different varieties include leaves of an inch to two feet across. Foliage colors range from bluish green to yellow to almost white, and variegated. They're almost trouble free (although slugs love to eat holes in the leaves), and very hardy, a great solution for very shady areas interplanted with astilbes and ferns.
Iris Elegant, fragrant champions of the late-spring garden, beautiful blooms top stems 6 inches to 4 feet tall in a multitude of colors. Among the most popular are bearded irises with large heads, and Siberian irises, which have smaller blooms. The knife-like foliage adds a pleasing texture to the garden even after the flowers are spent.
Lily Many different lilies - types, forms, species - are hardy in Zone 4 and some like shade. Try canna lilies (you'll have to dig up the tender bulbs each fall, but it's worth it) for very tall - up to 12-foot - flowers and striking foliage, Oriental lilies for exquisite form and fragrance or Asiatic lilies for a progression of beautiful summer blooms - just to name a few. This is a flower that can really hook you - you may want to collect more and more.
Monarda (Bee Balm) Here's another easy hardy, tall pink, purple, red or white bloomer for your garden. This native plant, a member of the mint family, attracts butterflies, and multiplies heartily in the garden by seeding and undergrown stems (you may have to divide them often so they don't overtake other plants). Some varieties are susceptible to powdery mildew, so look for the many new mildew-resistant varieties.
Peonies A stalwart in any garden, even if you have no other flowers. It will last for 40 years or more, giving you big, sumptuously fragrant blossoms in spring. Several varieties and colors range from white to reds and corals to bi-colors. Very showy, great cut flowers.
Phlox Plant enough of these big-headed, sturdy, 3-foot-tall flowers and each early August morning will be filled with the loveliest fragrance. They spread nicely, allowing you to divide and share with friends or sprinkle around your yard after a few years. Available in white, red, pink, and violets, some bi-colored. They'll take just about any soil conditions, although they like sun. Look for the newer, mildew-resistant varieties.
Sedum An easy perennial that adds charming interest throughout the growing season - from pale silver-green foliage in spring until the pink, red or yellow blooms of summer that turn to russet before the snow falls. There are several varieties, including the 2-foot 'Autumn Joy,' one of the most popular, and 'Dragon's Blood,' only about 4 inches tall. Annuals for sun Ageratum Great little edging plants in blues, purples, pinks or white can form a nice wave of color all summer; can take part shade. Alyssum What garden is complete without sweet alyssum, a fragrant, small border plant that works well in the garden or in a container? Available in white, pink, purple or a mixture, it can self-seed the following spring. Asters Available in many flower styles, from daisy-like to mum-like, and colors, in the white-pink-purple range; great for cutting, but won't rebloom after being cut. Cleome (spider plant) A 4- to 6-foot plant with pink, purple or white heads that dance gently in the wind; works well with cosmos at the back of the garden and can be used for bouquets. It will self-seed and produce blooms the next year throughout the garden. Cosmos Tall, lacy back-of-the garden plants, available in pinks, purples and whites; these tend to self-seed if you leave the spent heads on, or scatter seeds from heads you pick off. Geraniums This plant -- a perennial in warmer climates -- comes in many varieties available in wonderful colors, sizes, leaf forms -- ivy-leafed, for example, and variegated -- called zonal; can take some drought. Heliotrope This is one of my favorite garden flowers, with fragrant purple flower clusters amid deep purplish-green leaves; there's a white variety also. It's about 15 inches tall, and works in bouquets if quickly plunged into water after cutting. Lobelia Masses of tiny white, pink, brilliant blue or purple flowers look great at the front edge of the border, or trailing from a container; takes part shade. Marigolds One of the most popular annuals, with many selections available, ranges from petites to giants, 3 inches to 24 inches, and colors from pale yellow to burgundy, including variegated; there's also a white form. Has a pungent, not floral aroma. Morning glory Here's a joyful flower to come across every morning. This vine will climb any fence, trellis, shrub or tree if it gets plenty of sun and blooms profusely from midsummer. Each bloom dies the day it opens, but there'll be more tomorrow. It's available in a range of white to pink to blue, but I especially love "Heavenly Blue." Nasturtium This trailing plant shows its bright, edible, yellow-to-red blooms best in fairly poor soil; in fertile soil, you'll see mostly leaves. Good in borders, trailing containers and salads. Nicotiana Also known as flowering tobacco, this has big leaves and star-shaped white, pink or rose flowers; about 18 inches to 4 feet tall, it takes a big space in the middle of your border. Pansies Great spring and fall bloomers with lovely "faces" and fragrance; they tend to get leggy with smaller blooms as summer progresses and may keel over in heat. Makes a nice little bouquet or corsage. Petunias You'll find almost every color – from white through reds, pinks and purples, some pale yellow. It comes in single or double forms and grows anywhere from upright to trailing (the new 'Wave' petunias are fabulous trailers). Needs regular deadheading. Portulaca I like this moss rose as a ground cover for its bright colors and spreading habit in hot, dry areas. A happy, carefree plant. Salvia Spiky blooms add height to kitchen bouquets, available in many colors these days, from apricot to lavender, blues, pinks, red, purple and white. I especially like the blue Victoria for its long bloom and for bouquets. Scarlet runner beans These bean vine plants make a nice annual fence cover with bright red blooms that precede tasty big flat beans. Snapdragon Here's a long-time favorite available in heights from 8 to 36 inches and a rainbow of colors from white through reds, pinks, yellows and orange. A great cutting flower that blooms all summer; a great bedding plant in masses. Sunflowers These giants of the garden are available as volunteers throughout your yard if you fed birds sunflower seeds through the winter. Sow seeds in early spring for many varieties ranging from a foot to 12 feet tall (if you can keep the squirrels away from them). Sweet peas Get these seeds in the ground early – April, even – for an early summer crop of delicious-smelling multi-colored delicate blooms. Some of the stems are 8 to 10 inches long on this vine plant, and picking bouquets of them encourages more blooms. Some varieties die when it gets hot, and even the "heat-resistant" aren't going to be really happy in hot weather. Zinnias These fabulous flowers come in a great range of color and height, from hot reds and pinks to more tender pinks to white, some striped; these grow well from seeds planted in early to mid May. Annuals for shade Impatiens A wonderful bloomer in single or double form, in many colors and bi- and tri- colors. Small plants get big and poofy in a shady border or container, droop when they're thirsty, perk up when watered. Vinca A nice short plant with white or pink flowers; a good edging plant with dark, glossy leaves. Browallia Star-shaped blue or white flowers cover these 10-inch plants in shady locations; nice in a shady border or container. Begonia (wax) Small plants with clusters of white to pink and red clusters of flowers do well in mass plantings in shady borders or containers. Begonia (tuberous) Large, single or double flowers in delicious colors - yellow, white, apricot, red, pinks, bi-colored - look great in shady planters, and hanging baskets; you can overwinter the bulbs for possible bloom again next summer. Coleus Grown and used mostly for their unusual foliage – ranging from pale green to variegated pink and bright green to deep burgundy, with serrated to ruffled edges; a nice fill-in for very shady spots. Pinch off puny blooms in late summer to keep foliage lush. FuchsiaWhat a glorious hanging-basket flowering plant! This can't take much hot sun, but thrives in the shade and produces the most interesting bi-colored flowers of fuchsia-and-purple, pink-and-white; dark-pink-and-light-pink - great combinations, each bloom looking like an intricate chandelier. Polka-dot plant A foliage plant with green or nearly-white leaves dotted with pink splashes; a nice, spreading ground cover in woodland settings. Now that we've planted some ideas in your head, it's time to dig out your gardening tools and get your garden in full bloom.
County Extension For gardening help or information, check with a certified Master Gardener or a horticulture expert at your county's Minnesota Extension Service office: Anoka County: 755-1280; Carver County: 442-4496; Dakota County: 891-7700; Hennepin County: 374-8400; Ramsey County: 704-2070; Scott County: 445-5055; Washington County: 439-0101 Minnesota Landscape Arboretum The 935-acre arboretum on Hwy. 5 in Chanhassen is a research facility of the University of Minnesota. Visit its gardens, woods and prairies, attend gardening classes, check out its fine horticultural library or ask an expert. 443-2460. Yard and Garden Line The Minnesota Extension Service answers questions on insects and gardening from 9 a.m. to 1 p.m. weekdays. Each call to (900) 988-0500 costs $2.99. Info U For recorded information on horticulture, pests, water quality, home maintenance, food and nutrition, finances, parenting and other topics, call Minnesota Extension's Info U line, 624-2200. Minnesota Horticultural Society The society, 1755 Prior Av., Falcon Heights, offers classes and seminars, Minnesota Horticulturalist magazine and an information line. 643-3601.