Garden Resources

Seasonal Gardening Tips

Samara Eisner, Horticulturist
Mar 7, 2023

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Gardening Tips

Gardening tips for every season. 

WINTER GARDEN TIPS

December

  • Winter is an excellent time to prune most trees and shrubs to improve shape and vigor. Deciduous trees are easier to prune when the leaves are off, as branch structure is clearly visible and you can better picture the impact of removing a given branch.
  • Container gardening should be enjoyed all year long. Make exciting winter arrangements with material such as red twig dogwood, juniper, arborvitae, ornamental grasses, winterberry...the list is endless. Use frost-free containers such as stone or plastic. Terra cotta or ceramic pots are more likely to be damaged by cold temperatures.
  • Install tree and shrub protection around your prized trees and shrubs. Plastic coated, 4' wire fence works great to keep out deer. Hardware cloth, with 1/4" holes works well to keep out the smaller critters such as mice, voles, and rabbits. Be careful that your fencing material isn't too snug against the trunk or branches.
  • Loosely cover tender perennials and evergreen perennials, such as hellebore and lavender, with pine boughs; boughs not only make great winter mulches, they help catch and hold snow, which is a great winter insulator.

January

  • Think about other options for your dried-out holiday tree. Recycle it! Place the tree next to bird feeders for added shelter. Ask your neighbors to donate their tree to create a cozy winter retreat. If you haven't done so, use the boughs to cover tender perennials.
  • Remember to check on stored tender bulbs, rhizomes, and tubers every few weeks. Make sure they're not drying out or rotting in storage. Keep a thermometer near - temperatures should be between 35F and 50F. Too much warmth, in combination with too much moisture, will initiate early growth.
  • Avoid using melting salts on ice - they may damage plants. Use kitty litter, sand, or ash to create traction.
  • Evergreens, such as arborvitae, yew, and boxwood, are easily damaged or misshaped by heavy, wet snow. Gently remove snow immediately after a fall (before it freezes onto branches) with your hand or soft broom. Limbs damaged by snow or ice should be pruned promptly to prevent bark from tearing.
  • Check tree and shrub protection hardware. Winter wind can cause friction wounds on young or thin woody tissue.

February

  • For a touch of spring, flowering branches may be brought inside and forced to bloom. Keep in a cool room with fresh water. Excellent trees and shrubs to force include crabapple, forsythia, pussy willow, and serviceberry. Experiment with other species; trees and shrubs that flower before leaves emerge are the best for forcing.
  • To keep forcing water fresh, try this simple recipe of 1 T. vinegar, 1 T. sugar and 1 t. bleach for one quart of water.
  • As the ground thaws, be sure to watch that perennials are not heaving out of the ground. If this occurs, gently push plant roots into the ground and cover with extra mulch if necessary.
  • Begin seeding slow growing plants such as ageraturm, impatiens, verbena, geraniums, begonias, salvia, and petunias.

SPRING GARDEN TIPS

March

  • If young trees are wrapped for winter protection, remove the wrap after the snow disappears. Wrapping interferes with photosynthesis which can occur in the bark of young trees.
  • Cut back perennials that were left for winter interest such as ornamental grasses, sedums, and coneflowers.
  • Save room on a bright windowsill for sowing parsley seed. Seed of snapdragon, impatiens, dusty miller, dianthus, and stock can also be started indoors.
  • Be careful not to rush into perennial beds planting and dividing because the ground could be too wet, resulting in compacted soils. Use this time to prepare for the upcoming season by cleaning and sharpening tools.
  • Visit Olbrich's Schumacher Horticultural Library, browse through the collection, and choose a new garden project. For example, design a rain garden, incorporate herbs and interesting vegetables into your beds, or plan a butterfly garden as one of your creative garden projects.

April

  • Mid-April is an excellent time for transplanting and dividing perennials. It's best to wait until new growth is 2 to 4 inches tall to ensure plants will successfully re-establish.
  • Cool season annuals may be planted to add color to the garden. Early season crops like pansies, calendula, lobelia, and lettuce make excellent container plantings.
  • Flowering branches such as crabapple, pussy willow, apple, cherry, willow, and forsythia can be brought inside and forced into bloom.
  • Early spring, after the ground has thawed, is a great time to plant trees. If possible, avoid planting on extremely hot, dry, and windy days to reduce water stress on trees. Be sure new plantings don't dry out.
  • Get an early start on weeding...the early bird catches the worm!

May

  • Mark your calendars right now...don't forget to visit Olbrich's Plant Sale with the Pros. Treat yourself and your garden to some of the newest and greatest plants on the market!
  • Construction season is on its way. If home construction or additions are on your agenda, protect your trees from soil compaction, grade changes, and unnecessary stress. Fence and mulch out to the drip line (or perimeter of the outer branches) to safeguard the tree's sensitive root system.
  • Mulch is magic! Mulch beds and around trees (avoid mounding mulch against the trunk) about 2 to 4 inches to reduce weeds, help retain moisture, and incorporate organic matter into the soil.
  • If planted early, be prepared that tender plants may need to be covered if there's a chance of frost. In May, there's still a 50-percent chance of frost in southern Wisconsin.
  • As tulip, daffodil, and other spring flower bulbs fade, deadhead flowers to keep beds looking fresh. Resist the temptation to cut back foliage too early. Bulb foliage should only be cut back after it has turned yellow or flopped over.

SUMMER GARDEN TIPS

June

  • Summer is finally here! Boy do we deserve it. Take advantage of every garden minute. It's not too late for transplanting and dividing. Take advantage of established plants - divide and use to fill in bare spaces in the garden or mix it up and add a perennial division to a container.
  • Experiment with an annual variety that's new to you. Try summer snapdragon (Angelonia), cuphea (Cuphea sp.), or globe amaranth (Gomphrena globosa) in a sunny location. Wish bone flower (Torenia), coleus, and fuchsia are great additions to a shady site.
  • Go big and bold: add a tropical accent to your garden or favorite container. Banana (Musa), honeybush (Melianthus), and fiberlily (Phormium) are some of our favorites here at the Gardens.
  • A common mistake when designing containers is leaving out the foliage. Foliage adds interest and texture - it gives the container a little extra kick! Some great foliage plants are alterananthera, artemisia, and spurflower (Plectranthus sp.). Silver sage (Salvia argentea) is my current foliage favorite!

July

  • Need some new container ideas? Visit Olbrich Gardens! Every year more than 500 containers are displayed throughout. Also attend Olbrich's Home Garden Tour and collect ideas for your home garden.
  • Deadhead your containers throughout the season for continuous bloom. Removing spent flowers allows plants to use energy for flower production, rather than seed.
  • Tame aggressive plants such as sweet potato vine (Ipomoea), shrub verbena (Lantana), and petunias. These plants are great additions to a container, but if allowed to roam, they will take over and smother other less aggressive plants. It's ok to cut back hard; you'll be surprised how quick they'll grow back.
  • If a plant isn't performing as you had hoped, remove it and pop it in another container or allow other plants to fill in the space.

August

  • Stay one step ahead by starting to take cuttings from annuals you want to overwinter indoors. Plants are healthier and will root faster than they will later in the season.
  • Containers need more attention later in the season. Established containerized plants will need to receive more frequent watering than plants in the ground.
  • Due to the sterile nature of artificial potting mixes, your containers would appreciate liquid fertilizer later in the season. A balanced liquid fertilizer every two to three weeks will make a big difference.
  • Extend the life of your containers by removing plants that won't tolerate a fall frost. Identify them early and switch them out for frost tolerant annuals such as pansies, snapdragons, and ornamental kales and cabbages.

FALL GARDEN TIPS

September

  • Fall is the time for planting and transplanting - sunny days, cool temperatures, and warm soil promote root development. Divide spring and early summer blooming perennials like iris and peonies.
  • Take cuttings of geraniums, begonias, scented geraniums, coleus, lantana, fuchsia, and other tender plants for over-wintering in a windowsill.
  • Tropical plants may be brought indoors and over-wintered as houseplants in a bright sunny location.
  • Lift elephant ears, gladiolus, dahlias, cannas, caladiums, and tuberous begonias after frost. Cut back, remove soil, and store in peat moss, newspaper, or sawdust in a cool, dark area for winter.
    Keep on weeding! Weeds are still trying to set seed or store energy for the coming winter.

October

  • This year try planting 'minor bulbs' in addition to tulips and daffodils like Siberian squill, glory of the snow, snowdrops, and puschkinia.
  • Impress your neighbors by adding bulbs to your spring containers. It's a great way to tie your spring landscape to your containers.
  • After a killing frost, cut perennials to the ground and remove 'melted' annuals. Remove plant material to reduce the over-wintering of insects and diseases.
  • Leave some plant material standing for winter interest. Birds and other wildlife with enjoy standing black-eyed Susan, purple coneflower, gayfeather, and little bluestem. Keep a journal of which plants attract songbirds into your garden.
  • If you are considering planting new beds or changing bed outlines, take advantage of this precious time. Spring leaves little time for this activity. You will thank yourself next April, especially if we're having a wet spring.
  • Collect dried material for winter decorations. Dried peppers threaded on a string of fishing line make a beautiful garland. Basil flowers, grass seed heads, strawflowers, amaranthus, statice, and celosia all dry well and can later be used to decorate a holiday tree with natural plant material.
  • Don't forget to drain the water from garden hoses at the end of the season. Coil and store in a location where they won't freeze.

November

  • Place wire screen around fruit trees, roses, witchhazels, and other susceptible shrub and tree trunks to protect from rodent damage.
  • Water all needle and broadleaf evergreens one last time before the ground freezes. Winter wind and sun will continue to demand water from these plants through their foliage all winter. Excess water loss can lead to 'winter burn' or death.
  • Don't forget to bring in your terra cotta pots. Winter frosts and harsh weather can cause pots to crack and shorten their life span.
  • Do you have a garden action notebook? This is the time to make 'action' notes. Before you forget what plants you want to divide in the spring, what plants you wanted to move to new locations, and plants you want to research over the winter, make a few action notes. You'll appreciate the reminders in the spring.