Colorado Gardening Tips

 

February
• Thin old, overgrown deciduous shrubs before they start to bud out or bloom.
• Prune away any branches that have been injured or torn because of ice and snow.
• Deep water trees, shrubs and roses as needed.
• Gently brush the snow off trees and shrubs.

March
• If you didn't rake leaves or remove old fruit from fruit and deciduous trees in the fall, do so now.
• Check evergreen for browning and deciduous trees for buds that have died. Prune, don't shear deciduous trees.
• Wet snow on evergreen trees can be most damaging at this time of year because of weight. Gently sweep the branches.
• Although not necessary, you can prune evergreen trees and shrubs on upward growing branches this month.
• Prune junipers.
• Plant container and balled-and-burlapped trees and shrubs late this month.
• Control insects like aphids, mites, and scale by raking up dead leaves from the previous season. Better safe than sorry!
• Plant bare-root, or transplant existing roses in late March or as soon as the ground is workable.
• Check lawn and garden beds for evidence of voles and treat, if necessary.
• Remove thatch, excessive mulch, tall grass, old root vegetables, and dropped fruit left over from last season.
• If there is no snow, rake and aerate Bluegrass and Tall Fescue lawns.
• Apply pre-emergent herbicide to your lawn if you've had crabgrass problems in the past. Do it before mid-April when the crabgrass germinates.
• Aerate and fertilize - thick lawns are less prone to crabgrass. Fill in any blank spots in the lawn so crabgrass can't invade.
• In late March, sow seeds of peas, onions, carrots, lettuce, spinach, and radishes outdoors. Plant transplants (i.e., seedlings) of broccoli, cabbage, and kale.
• Prepare the soil for all Colorado gardens, except those in the mountains, where you should wait until May.
• Mow lawn to no less than 2" and never cut any more than one-third of the growth.
• Water plants, trees, shrubs and lawn infrequently, but thoroughly.
• Cut back ornamental grasses to 6” – 12” above ground.

April
• If you haven't already done so, cut back perennials (except evergreen perennials-plants that stay green all year) from last year. With a sharp pair of scissors, remove dead plant material all the way to the ground.
• Prepare to activate the sprinkler system.
• If you haven't already done so, aerate and fertilize the lawn.
• Once the flowers on the bulb plants like tulips or daffodils have died, do not cut back the foliage until it has turned yellow.
• Divide fall-blooming perennial plants and bulbs in late April.
• Mow lawn to no less than 2" and never cut any more than one-third of the growth.
• Water plants, trees, shrubs and lawn infrequently, but thoroughly.
• Plant summer-flowering bulbs.
• Seed or overseed wildflower beds if this wasn't done last fall.
• Cut back ornamental grasses at the base of the plant.
• Plant and transplant perennials on a cloudy day or early evening. Plant at the level of the base of the stem.
• Put out seed for hardy annuals such as bachelor's button, calendula, larkspur, pansy, and snapdragon.
• Prune branches on old, overgrown shrubs. Do not prune shrubs that are starting to bud out - wait until bloom.
• Remove tree wrap.
• Plant and transplant bare-root trees and shrubs.
• Fertilize deciduous trees and shrubs.
• Gradually start to remove the mulch mounding from rose bushes late in the month.
• If you haven't already done so, prepare the soil for all Colorado gardens.
• Begin to treat weeds.

May
• Mulch around flower and shrub beds to conserve moisture and keep down weeds.
• Mow lawn to no less than 2" and never cut any more than one-third of the growth.
• Water plants, trees, shrubs and lawn frequently, and thoroughly.
• After the 15th, put out annuals and perennials that have been over wintered indoors in pots.
• Plant annuals at the same depth as in the container (or slightly higher in very clay soil) in soil-amended beds.
• Set out any seedlings sowed indoors.
• Check plants for aphids and treat if necessary.
• Mow (at highest setting) ground covers to clean them up and remove winter burn.
• Pinch back mums so they are bushy in the fall.
• Do not transplant ornamental grasses after the middle of July.
• When you buy plants for your garden (flower or vegetable), look for a six-pack of seedlings that are not dried out or soaking wet, not wilted, yellow, or spindly.
• When you plant annuals, dig individual holes for plants in amended soil. Make sure the plant and roots are wet, remove the container, and plant in the hole at the same depths as it was in the container, or slightly higher in heavy clay soil. Soak the ground heavily and mulch.
• If you shear hedges, never take off more than one-third of the growth. The top should be narrower than the base so the sun reaches all areas.
• Deadhead lilacs after they finish blooming.
• Snap off new candles on evergreens to maintain compact growth.
• Mulch around trees and shrubs.
• Fertilize rose shrubs.
• Prune back rose shrubs and remove mounding that remains.
• Plant container roses after the last frost.
• Dead stems on roses should be cut back all the way to the point the wood is "clean" (there is no brown center). Live stems also should be pruned back until the wood is clean. Use a pair of rose pruners. Don't be afraid to prune severely at this time.
• Sod new lawn.
• Seed any dead areas in your lawn caused by mold, disease, or insects.
• If needed, apply broadleaf weed killer on lawn.
• Purchase vegetable transplants and seeds for direct sowing.
• Plant radishes cucumbers, zucchini, and beans from seed. Reseed beans every few weeks to extend harvest.
• If you want pumpkins by Halloween, plant seeds now.
• Plant tomatoes and peppers from transplants at the end of the month.
• From transplants, plant herbs like basil, parsley, and chives. Try growing dill from seed.
• From transplants, plant flowers like marigolds, nasturtiums, and pansies in the paths, between rows, and around perimeter.
• Interflowering flowers and herbs throughout a kitchen garden may help distract and confuse insect pests throughout the summer.
• If you are growing tomatoes for the first time, start by purchasing the more common varieties found in garden centers like Champion or Celebrity. Plant up to the first set of leaves, and follow the tag for the distance in between plants. Place extra-large cages around tomatoes after the second week (the tomatoes will eventually grow into them). Tomatoes need plenty of water, consistently warm weather, and the soil must be kept evenly moist to produce the best fruit.
• Plant climbing vines in the early part of this month for great result the rest of the summer. There are some varieties of climbing vines that grow well in Colorado: clematis, honeysuckle, woodbine, Boston ivy, grape, and hops. Trellis climbing vines for show, easier maintenance, and to keep them from crowding out other plants, trees, and shrubs.
• Replenish organic mulches.
• Continue to weed your garden before weeds get too big or too numerous.
• In late May, plant annuals in containers and set in bare spots in landscape.

June
• Fertilize annuals and perennials with nitrogen-based fertilizer.
• Check drip and lawn system. Remove any emitters that are over watering, add emitters to areas where the soil is dry.
• Sow annual flower seeds like cosmos and zinnias, into the garden.
• Deadhead flowers as they fade to promote continuous bloom.
• Note places in your landscape that could be filled next year with bulbs. Plant in the fall for spring bloom.
• Fertilize rose shrubs after the first round of flowers has started to die.
• Remove rose shrub suckers that have come up from the roots.
• Mow lawn no less than 2" and never cut any more than one-third of the growth.
• Finish harvesting spring-planted cool season vegetables such as peas, lettuce, and spinach.
• Cut back remaining bulb foliage.
• Look for radishes planted in May to be ready toward the end of this month.
• Check for diseases or insects that may be attacking plants.
• Weed your garden once a week.
• Keep small stones swept off patios and walkways for safety.
• Water your garden frequently, and thoroughly.

July
• Mow the lawn to no less than 2-1/2 " in height, never cutting more than one-third of the growth.
• Do not use high nitrogen fertilizer on trees from the middle of July through February of next season.
• Make sure the garden is well-mulched to protect plants during the heat of the day.
• Pinch mums only until the end of the month, then stop for better fall flowers.
• Divide bearded iris bulbs.
• To produce larger fruit, thin the tiny fruits on your trees to a hand-span between each.
• Fertilize roses.
• Hot, south-facing slopes of the lawn need to be properly watered because they will get dry at this time of the year.
• Begin to harvest vegetables and herbs this month for great summer eating.
• Spider mites really begin to emerge this month, monitor your plants, trees, and shrubs, to treat when necessary.

August
• Make sure trees and shrubs get enough water during August.
• Pay particular attention to good watering practices this month. Stressed areas in the full sun, or on south or western slopes may need extra watering.
• Weed your garden frequently. Watch to see that weeds do not grow so large that they flower and drop seeds (causing more weeds!).
• Continue to deadhead, pinch, and cut annuals and perennials.
• Cut back spindly annuals and fertilize for another spurt of growth.
• Purchase bulbs for fall planting.
• Select and cut flowers, grasses, and leaves that you want to dry for display in arrangements.
• Remove evergreen branches that are dead or diseased.
• Remove branches on deciduous trees that are dead or diseased.
• Last month to fertilize rose shrubs. Do not fertilize after the middle of the month.
• Mow lawn to no less than 2 1/2" and never cut any more than one-third of the growth.
• Continue harvesting tomatoes, zucchini, basil, and dill.
• Begin to harvest beans, peppers, and cucumbers.
• Make certain plants are watered adequately on hot August days.
• Watch for pests, like cabbage butterflies and tomato worms.
• Watch for spider mites on tomatoes and peppers. Hose off with insecticidal soap in early morning.
• If you have a water feature that requires mats, clean them now.
• Keep small stones swept off patios and walkways for safety.
• Make sure plants in the garden are getting adequate water this month.
• Powdery mildew is now emerging on roses, lilacs, and perennials; treat with fungicide as needed.

September
• Plant new perennials.
• Plant or transplant evergreens before the weather turns cool.
• Begin paying attention to the weather forecasts for predictions of early frosts. Cover plants if necessary.
• Water as needed. Be sure to check the ground so you don't over water.
• Transplant and/or divide peonies. Caution: Peonies hate to be moved! To transplant and/or divide peonies: Dig up the entire plant, making sure to get all the roots. At the crown of each plant, there will be pink buds. Use a knife to divide the plant so that there are no more than three buds in each division. Dig a hole in amended soil, and plant your divided peonies close to the surface, covering the buds with only 2" of soil. Water thoroughly after transplanting. Peonies like sunny or partly shady locations.
• Transplant and/or divide spring and summer blooming perennials (but not fall perennials).
• Water roses when soil is dry.
• Mow lawn to 2" and never cut any more than one-third of the growth.
• Reseed parts of lawn that need it.
• Continue harvesting tomatoes, cucumbers, beans and zucchini.
• Begin to harvest peppers and carrots.
• Harvest marigold, nasturtiums, and zinnias before first frost.
• Harvest all green tomatoes before first frost. They will turn red after removal from the plants.
• Harvest cabbage, carrots, and brussel sprouts after the first mild frost.
• Weed your garden every few weeks up until the first frost.

October
• Plant hardy bulbs for spring blooming.
• Winterize the irrigation system. In Colorado, it is necessary to "blow out" all the water in your sprinkler system each fall. This prevents the water lines from freezing and then breaking during the winter.
• Seed your wildflower garden now for spring blooming.
• Bring in any pots of annuals that you plan to over winter.
• Dig up gladioli, cannas, dahlias, and ranunculas when leaves begin to turn yellow. Store them for winter. Store in packing material (peat moss, vermiculite, sand, sawdust) in a cool (about 50 degrees), dry place. The bulbs should be periodically sprinkled with water so they do not totally dry out. If bulbs become diseased or start rotting, throw them out; if too wet or sprouting, move to a dryer place and discard packing material.
• Water roses when soil is dry.
• Fertilize the lawn and aerate.
• Mow lawn for the last time in Mid-October. Mow down to 2".
• Harvest brussel sprouts and pumpkins after the first frost.
• Pull vegetable plants.
• After the leaves on trees have changed color and fallen, continue watering all trees and shrubs until the first hard freeze.
• Plant container and ball-and-burlapped trees and shrubs.
• Tree leaves should be raked and either discarded or composted.
• Dig the hole in late October for planting a live Christmas tree after the holiday season in December.
• Do not water or fertilize trees and shrubs as much so that they will begin to get the signal to harden off.
• Plant bulbs like tulips, hyacinths, daffodils, and crocuses in the fall for blooming next spring.
• Pumpkins are ready to harvest when they are orange in color and the skin is hard.
• When harvesting the pumpkin, leave several inches of stem on the stock.

November
• Mulch around plants.
• Brush heavy snow off tree and shrub limbs.
• Leave the snow on low-lying shrubs to act as an insulator.
• Check the stakes on all trees to make sure they are stable, secure, but not too tight around the tree.
• Mulch rose bushes in early November or when the temperature in your yard has dropped to 22 degrees.
• Spade vegetable garden and add organic matter which will break down by next spring.
• Deep water trees, shrubs, and roses as needed.
• Mulch young or newly planted trees and shrubs.
• Purchase spring bulbs for forcing and indoor winter blooming.
• Cut back perennials from last year so they will bloom better.
• Plant pots with hardy Pansies or Evergreen arrangement of twigs and pinecones.

December
• Add lighting to your landscape.
• Reduce watering of plants as the days become shorter. Plants can be over watered if you are watering as much as you do in late spring, summer and early fall.
• If you haven't mounded your rose shrubs with 8"+ of mulch, it still isn't too late.
• Set out food for birds that may call your garden home. Location, location, location! A bird feeder should be put where you can see the birds, but not near trees because the food will encourage squirrels. If possible, put the feeder near a protected overhang, but not so close to the windows that birds will fly into them. Birds like to eat suet, and black oil sunflower seed is popular among most species of birds. Providing water to your feathered friends is a nice bonus, but you will have to contend with ice and freezing each day. If you plan to feed the birds, be committed - for their sake!
• Deep water trees, shrubs and roses as needed.