Month by Month Yard Maintenance

The following information is provided for residents in the Twin Cities area of Minnesota.

Spring is coming soon.  To get you in the gardening mood, fertilize your houseplants and repot in larger containers, if necessary.

Garden - flowers, perennial, vegetables, landscape beds:

• Start planning for your spring garden.  This is the time to purchase seeds.

Trees/Shrubs:

• Finish dormant pruning of ornamental shrubs
• Prune diseased or damaged trees and shrubs
• Shape most deciduous shrubs.  (do not prune: Snowmound and Bridalwreath Spirea, Chokeberry, Lilac, Magnolia, Mockorange, and Wiegela)

Lawn Care:

• Stay off soggy lawns to avoid making impressions, which could permanently damage the level surface of your grass.

Misc.:

• Plan your upcoming landscape improvements.

Garden - flowers, perennial, vegetables, landscape beds:

• Uncover roses, perennials, and spring bulbs.
• Add compost to the garden.
• Plant cool season vegetables

Trees/Shrubs:

• Remove any wrapping from thin-skinned and ornamental trees.
• Prune oak trees before April 15 or wait until after September 1, to prevent the transmission of oak wilt by picnic beetles.  If oaks are accidentally damaged and must be pruned during this period, immediately apply a tree wound dressing.
• Fertilize trees, shrubs, and evergreens.  ***(see notes on new Minnesota Fertilizer laws at bottom of this document)
• Purchase only disease resistant plants.
• Spray fruit trees, Hawthorne, and Crabs, and Cottoneasters with dormant spray

Lawn Care:

• When the ground is no longer soggy, set your lawn mower to a lower setting and mow off the old grass (to approximately 1 1/2 inch long).  This will encourage early greening.
• Apply the first fertilizer to your lawn.  *** (see notes on new Minnesota Fertilizer law at bottom of this document)

Pest Control and weed control:

• Review insect problems from the previous year.  Determine when insects are most likely to arrive, so treatment will minimize damage to plants.  Preen or any pre-emergent can be applied to shredded wood mulch beds to help reduce the annual weed explosion.

Misc.:

• Time to activate your sprinkler system.

Garden - flowers, perennial, vegetables, landscape beds:

• Plant warm season vegetables.
• Plant ground covers where shade makes it difficult to grow grass.

Trees/Shrubs:

• Starting in early May, watch for caterpillar-like sawfly larvae on pines.  Treat them while they are still small, 3/8 inch or less, especially if they are numerous.
• Prune Mugho Pines when the lilacs are in full bloom

Lawn Care:

• Regular mowing is a must.  Try to trim off now more than one-third of the total grass height with each mowing.  Leave the clippings on the grass.  They provide your lawn with important nutrients.
• Do not use weed-killers on newly seeded grass until fall or next spring when your lawn is well established.
• Four to six weeks after your first lawn fertilization, apply crab grass preventer

Garden - flowers, perennial, vegetables, landscape beds:

• Treat fruits and vegetables only with pesticides that are registered for those plants or refrain from eating the produce.
• Garden - thin plants in garden to promote proper maturity and growth.
• In late June, after the soil has warmed, add mulch to your vegetable garden to prevent weeds from growing.  Now, instead of weeding, you'll have more time to enjoy your summer and your beautiful garden.

Trees/Shrubs:

• Prune spring flowering shrubs and ornamental trees after they have finished blooming.
• Trim evergreens and hedges.

Lawn Care:

• Spray broadleaf weeds on lawns.  If possible, spray only the weeds by spot application.

Pest Control and weed control:

• Begin control for squash vine borers in late June or as vines begin to run.  Dust developing vines weekly with methoxychlor until about mid-August.
• Ash plant bugs cause whitish or yellowish speckling on the upper leaf surfaces of ash trees.  Ash plant bugs only affect the tree's appearance; control is unnecessary for the tree's health.

Garden - flowers, perennial, vegetables, landscape beds:

• Remove dead foliage from Spring bulbs.
• The summer heat is on, so a weekly (or more frequent?) watering is important for young trees, shrubs, vegetables, and flowers.

Trees/Shrubs:

• Water young trees, shrubs, vegetables, and flowers weekly or the summer heat will take its toll.
• Maple trees can be safely trimmed at this time.  

Misc.:

• Take a break from gardening.  Sit back, relax, and take in the beauty of your well maintained yard.

Garden - flowers, perennial, vegetables, landscape beds:

• Remove faded flowers to encourage more blooms.
• Pick fruits and vegetables as they ripen.  Remove overripe fruits and vegetables to discourage insects, including wasps.
• Continue to weed flower and vegetable gardens.  Weeds not only compete with desired plants for moisture and nutrients, they can harbor insect pests and drop seeds for next year.
• Nip off faded flowers whenever possible to avoid seed production.  It wastes energy, and plants frequently slow down once they've produced mature seeds.  Remove not only ripe but overripe vegetables for the same reason.
• Make plans now for your spring bulb garden.

Trees/Shrubs:

• Aphids feeding in August cause little damage to trees and shrubs.  Control is unnecessary in most cases.

Lawn Care:

• *** (see notes on new Minnesota Fertilizer laws at bottom of this document) Seed and fertilize your lawn between August 15 and September 15.  Aerate, de-thatch, and top-dress thin areas.  If planting a new lawn, this is the best time to seed.

Weed, Pest, and Disease Control:

• Spray annual weeds with broadleaf killer.  If possible, spray only the weeds with spot application.
• Growing plants where they will thrive can prevent many diseases.

Misc.:

• Repot any houseplant that has grown vigorously outdoors two or three weeks before bringing it back indoors.  Inspect for insects and begin any treatment that is needed.  Pay special attention to the undersides of leaves and axils where leaves join the stems.

Nature's growth is slowing.  Prepare your yard for the dormant season that lies ahead.

Garden - flowers, perennial, vegetables, landscape beds:

• Continue to weed garden areas.  The seeds that weeds drop now will result in new plants next year.  Do not add seedy weeds to your compost pile.

Trees/Shrubs:

• Fruit tree pruning is best done in late winter.  However, now is a good time to see diseased branches which should be removed.  Mark them with latex paint or string so they can be easily located later.
• This is a good time to plant evergreens.
• Continue to water young trees and shrubs.

Lawn Care:

• Apply a low nitrogen fertilizer, commonly referred to as a "starter/winterizer"

Weed, Pest, and Disease Control:

• Clean up leaves and other debris around your home to remove hiding places for sowbugs and millipedes.  This reduces the number of pests that enter your home.
• Mushrooms are common in many areas due to abundant moisture.  These organisms break down organic material and are generally beneficial.  Only a few are harmful to plants.  Most are not poisonous, but one should remove mushrooms that children or pets might find tempting, by picking or smashing them with a rake.
• Apply an 18" band of diazinon around your home's foundation to prevent the invasion of fall's unwanted guests.

Garden - flowers, perennial, vegetables, landscape beds:

• Cut Iris foliage back to about six inches and remove plant debris after the first frost.  This removes eggs, which helps reduce the number of Iris Borers next year.
• Protect roses in mid-to-late October.  Mulch bulbs and perennials after several hard frosts.
• Remove dead annuals.
• Plant spring flowering bulbs.

Trees/Shrubs:

• Prune honeysuckle branches infested with witches' brooms to remove over-wintering aphid eggs.
• Wrap young, thin barked trees to protect them from sunscald and rodent injuries.

Lawn Care:

• Rake leaves off of lawn to prevent disease.
• Continue to mow your lawn as long as it continues to grow.  Your last mowing of the season should leave your lawn at a height of about 2 inches.

Weed, Pest, and Disease Control:

• Store pesticides in dry areas that will not freeze.  Keep them locked and out of reach of children.

Misc.:

• As days grow shorter, ensure that your houseplants receive ample light.  Wash them, so dust doesn't act as a filter.  Then move them nearer bright windows, but not so close they touch the glass.  Direct sunlight is never a problem in fall and winter.
• Have your sprinkler system blown out.

Garden - flowers, perennial, vegetables, landscape beds:

• Protect roses and mulch perennials.

Trees/Shrubs:

• Continue to water new plantings and all evergreens until the ground freezes.

Misc.:

• This is the best time to contact me to discuss future landscape improvements.  

*** Twin Cities Metro area residents: please note new fertilizer restrictions effective January 1, 2004:

Starting January 1, 2004, the use of phosphorus cannot be used on lawns in the metro area.  (The middle number on a bag of fertilizer is the percentage of phosphorus.  From now on, that number must be 0).  These restrictions do not apply if a soil test from your lawn area shows that phosphorus is needed or if you are establishing a new lawn.  It is also permissible to use fertilizers with phosphorus on agricultural crops, flower and vegetable gardens, and golf courses (when applied by trained staff).

Green pond scum and green lakes can be attributed to phosphorus run-off.  Phosphorus provides food for algae, duckweed, and other aquatic plants that are a nuisance to our ponds and lakes.  Too many aquatic plants in a body of water can lower the oxygen levels, which can be detrimental to the fish populations.

If you think you need your soil tested, you can contact INFO-U (Minnesota Extension Services) by calling (612) 624.2200, then ask for message number 468.