After Planting  Bed Preparation Maintenance  Planting

Maintaining A Perennial Garden


Perennial gardens require less maintenance than lawns, but they do need regular care to look their best and stay healthy. The following tasks are arranged in order of frequency from weekly to annually.


Tools and Materials
Scissors or hand pruners
Water source, soaker hose or sprinkler
Hoe with small, sharp blade
Half-moon edger or garden spade
Lawn rake
Steel rake
Perennial plant fertilizer
Organic mulch


Remove spent flowers.

Using scissors or hand pruners, snip off flower stems just above a leaf or bud when they finish blooming to prevent them from forming seeds. Pick off damaged leaves.

Inspect for pests and problems.
Look for leaves with holes or ragged edges; sticky, discolored or spotted leaves; chewed or abnormally growing flowers or buds; or damaged stems. If you discover a problem, take samples of the damaged plant to a garden center with experienced staff or contact the Master Gardeners organization in your area for identification and advice.

Dig into the top 2 to 3 inches of soil with a trowel. If the soil is dry, water until the soil is moist to a depth of 6 to 8 inches. Soaker hoses and drip irrigation pipes apply water more efficiently than overhead sprinklers. Avoid wetting plant leaves late in the day to prevent the spread of some plant diseases.

Pull weeds.
Remove weeds as you see them on your daily or weekly inspection. Use a hoe with a small, sharp blade to slice them off just under the soil surface, or pull them by hand.

Edge the beds.
Keep the edges between your garden and lawn well defined and tidy with a half-moon edger or garden spade. Facing the garden, push the tool blade straight down into the edge of the turf about 3 to 4 inches. Pull the handle toward you to remove a wedge of soil. Repeat around the perimeter of the garden. Compost the turf scraps.

Fertilize and mulch.
Early in the spring, fertilize with a granular, slow-release fertilizer formulated for perennial gardens. Follow package recommendations for the correct amount to apply. Replace or renew organic mulch, such as shredded bark or leaves.

Seasonal clean-up.
In cold-winter climates, protect tender plants after the ground freezes with a 4- to 6-inch layer of loose mulch. Cut back perennials to within 8 to 10 inches of the ground after the tops die back or leave them uncut for protection against the cold. In spring, cut back all dead stems to the ground and rake out the debris.

Keep asters and chrysanthemums more compact by pinching a couple of inches off their growing tips when they reach 12 inches tall in spring and again in mid-summer.
If weeds get away from you, concentrate first on weeds with flowers or seeds, and then tackle one square foot at a time.
How to adjust Soil Acidity and Alkalinity

Why: Since plant growth is directly related by soil acidity, keeping soil in the correct pH range will keep a garden healthy and promote growth.

When: Testing for pH levels can be done during spring and fall. It is best to do testing before problems occur to prevent plant damage.

What: Use limestone to raise the pH level and iron sulfate or aluminum sulfate to lower it. Organic application of peat moss pine needles and oak leaves also lower pH.

  1. Test for soil pH. This can be done at home with test kits or soil samples can be taken to a lab or your local county extension service for testing.
  2. Most plants prefer a neutral pH of 6.0 to 7.0.
  3. Group plants that require the same pH levels.
  4. Recheck the pH of the soil annually and if problems occur.

Avoiding Soil Compaction

Soil may become compacted due to heavy pedestrian or equipment traffic causing poor penetration of water and air.

When: The best times to initiate a program to correct soil compaction are spring and fall.

What:  Tools for combating compaction are rotor tilling for gardens, core aeration by machine for turf, and earth worm preservation.

  1. Soil pH must be neutral (6 to 7) to promote earth worms.
  2. Avoid the application of earth worm toxic materials such as benomyl, diazinon , carbaryl and bendiocard.
  3. Mulch the root zone with wood chips, bark nuggets, or nut and seed hulls.
  4. If possible, the mulch should extend to the foliage drip line.
  5. Adding soil amendments such as peat moss or rice hulls to high traffic areas can help with combating compaction.

Fertilizer Basics

Fertilizers are used in commercial growing and in home gardening to supplement the natural nutrients in the soil.  Different fertilizers are used for different purposes.

There are three primary nutrients always represented by three letters in the same sequence.  N(nitrogen)  P(Phosphate) and K(Potash)

N - Nitrogen is a nutrient that encourages foliage growth.

P - Phosphate is used to increase plant strength of plant stems.

K - Potash is used to strengthen root growth.

The fertilizer bag will also tell you the percentage of these nutrients in the mixture.  This is represented by the numbers that appear after the nutrient letters.  For example, a bag with 5-10-0, has 5 percent nitrogen, 10% Phosphate, and 10% Potash.

While the percentage of nutrients is usually represented by the three numbers, most fertilizer manufacturers will provide a guaranteed analysis on the bag which provides information on the percentage of all ingredients in the bag.
Mulching  Basics

Why: Mulching helps to control weeds, retain moisture in the soil, insulate the ground during temperature fluctuations, add nutrients and improve the soil structure.

When:  During the spring, summer and fall but most importantly, after planting.

What: Types of mulches range from wood chips, shredded bark or nuggets, sawdust, pine needles, salt hay, buckwheat hulls, peanut hull, cocoa hull, leaves, straw, and  layers of newspapers.


  1. Some non-organic materials, such as small stones or geotextile mulches can also be considered for mulching.
    Select and define area in which to mulch.
  2. Place mulch around plants in large mounds with a shovel or by hand if needed.
  3. Spread mulch evenly around areas.
  4. The thickness of the mulch should depend on the type of mulch being used.  Wood mulches should be two to three inches in depth.
  5. Water mulch thoroughly after application.
  6. Because of decomposition of organic mulch,  nitrogen may need to be added. 
  7. An annual application of organic mulches is good practice for a healthy garden.

Protecting Plants from Winter Injury

Why: Valuable plants can be severely damaged or killed by winter conditions if not properly protected.

When: In the spring and fall it is important to protect plant from sudden drops in temperatures.

What: Pruning tools, mulch, burlap bags, and tree wrap

  1. Deep watering in the fall can provide needed moisture and help insulate plants.
  2. Place burlap covers over woody plants & trees to  protect against wind sun and snow.
  3. Trees susceptible to sunscald on trunks can be wrapped with protective “tree wrap”.
  4. Repair all trunk damage prior to winter to avoid frost cracks.
  5. Mulch plants before winter to protect against frost heaving.
  6. Increase the thickness of mulch around new transplants as they are at higher risk of frost heaving.

Watering Techniques

All plants need the correct amount of moisture to survive and flourish. While the water needs of plants varies by species, there are watering techniques common to most plants.

  • Water is vital to  root growth thus watering must be effective at the root level.
  • Too much water is as harmful to plants as too little water.
  • Water plants infrequently but water them deeply – to the roots.
  • Wind conditions,  humidity, soil structure, and heat all affect water absorption.
  • Mulching helps to protect soil from the sun and conserve moisture.

Watering Methods.   (There are 5 common watering methods.)

  1. Sprinkling is simply spraying water in the areas that plants grow.  It is easy, inexpensive but is inaccurate and wasteful.
  2. Soaking places a large amount of water in channels close to the plants but may damage smaller plants.
  3. Drip irrigation is done with soaker hoses or drip hoses that place small amounts of water near the roots over a long time period insuring that roots receive water.  It is an accurate method of delivering water but the equipment is expensive.
  4. Root irrigation puts water directly to the roots by injecting it through a rigid pipe connected to a hose. 
  5. Hand watering is the simplest method of watering and allows you to place the water where it is needed but in small areas.


Select your specific planting condition:

Verbena (some)
Phlox (some)
Dicentra (some) Bleeding-heart
Geranium (some) Cranesbill
Dianthus (some) Pinks
Veronica (some) Speedwell
Sedum (some) Stonecrop
Epimedium Barrenwort
Aegopodium Bishop's weed
Ajuga Bugleweed
lberis Candytuft
Nepeta Catmint
Houttuynia cordata Chameleon Plant
Gypsophila repens Creeping Baby's-breath
Ranunculus repens Creeping Buttercup
Polemonium reptans Creeping Jacob's-ladder
Lysimachia nummularia Creeping Jennie
Coronilla varia Crown Vetch
Lathyrus latifolius Everlasting Pea
Tiarella False Miterwort
Galeobdolon luteum Golden Deadnettle
Bergenia cordifolia Heardeaf Bergenia
Papaver nudicaule Iceland Poppy
Hedera Ivy
Pachysandra terminalis Japanese Spurge
Polygonum Knotweed
Stachys byzantina Lamb's-ears
Symphytum grandiflorum Large-flowered Comfrey
Santolina Lavender Cotton
Ceratostigma plumbaginoides Leadwort
Convallaria majalis Lily-of-the-valley
Liriope Lilyturf
Duchesnea indica Mock Strawberry
Alchemilla alpina Mountain Lady's-mantle
Oenothera missouriensis Ozark Sundrops
Mentha pulegium Pennyroyal
Vinca Periwinkle
Hosta Plantain Lily
Aubrieta deltoidea Purple Rock Cress
Euonymus fortunei 'Colorata' Purpleleaf Wintercreeper
Antennaria Pussy-toes
Arabis Rock Cress
Saponaria ocymoides Rock Soapwort
Chamaemelum nobile Roman Chamomile
Arenaria Sandwort
Artemisia schmidtiana Silver Mound Artemisia
Cerastium tomentosum Snow-in-summer
Lamium maculatum Spotted Deadnettle
Potentilla tabernaemontani Spring Cinquefoil
Hypericum calycinum St.-John's-wort
Clematis paniculata Sweet Autumn Clematis
Viola odorata Sweet Viola
Galium odoratum Sweet Woodruff
Armeria maritima Thrift, Sea Pink
Thymus Thyme
Petrorhagia saxifraga Tunic Flower
Asarum Wild Ginger
Achiffea tomentosa Woolly Yarrow

Gardening Basics

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