Maintenance

Mowing

When mowing, it is recommended that a 3-inch stubble height be left. With taller-statured grasses an even higher stubble height should remain. Various grass species respond differently to mowing. Rhizomatous species are stimulated by frequent cropping while bunchgrasses are often stressed or even eliminated by frequent cutting.

The mowing frequency and intensity will vary according to the species and intended use of a particular stand of grass:

• Manicured Lawn. Maintained at uniform height. Most sod-forming species are naturally short-statured.
• Biomass Removal. The purpose of mowing is to reduce the amount of dormant or dead stems and leaves for such purposes as fire prevention, reduction of potential snow drifting or just removal of mature plant material at the end of a growing season.
• Weed Control. Mowing, especially during the establishment year, can help with weed control by not allowing annual weeds to set seed.

Fire can be used as a substitute for mowing to reduce biomass when the grasses are dormant, i.e. late fall or early spring. Mature warm-season grasses, in particular, benefit from the removal of biomass, which stimulates the next year’s growth. Extreme caution must be taken to avoid property damage and annoyance to neighbors. Burning permits may be required - inquire locally.

Pruning/Trimming

Pruning is usually done on woody plants, but can also refer to the removal of seedheads and other mature plant parts from herbaceous plants.

Herbaceous Plants

Maturing seedheads can be pruned to stimulate secondary flowering or prolong vegetative growth later in the growing season. Mature specimen plants can be left to add winter color or aid in trapping snow. Otherwise, herbaceous material should be trimmed and removed in late fall or early winter. Herbaceous specimen plants left standing over winter should be trimmed in early spring to remove dead plant material and unwanted plant litter.

Woody Plants

At an early age woody plants should be pruned to conform with the intended use and landscape design. Trim to single stem or leave as multi-stem plant.

• Prune lower branches to provide lower stem sanitation or alleviate shading of adjacent ground cover plants.
• Prune disease or insect-affected plant parts to minimize spread.
• Remove rubbing, deformed, and dead branches.
• Prune interior limbs to reduce wind resistance
• Conifers should be pruned in spring or early summer.
• Deciduous trees and shrubs should be dormant-pruned in
  late fall or winter.

Fertilizer

Most of the arid and semiarid native plants do not need supplemental fertilization if established on natural soil conditions. If subsoil is exposed or the soil is very sandy, some fertilization may be warranted. Excess fertilization will increase biomass production, thus increasing soil moisture requirements for the plants.

Seedlings

Unless you are planting into a very raw, mineral soil, fertilizers (particularly nitrogen) should not be applied the seedling year—as you would only be feeding the weeds rather than the seeded plant material. However, the incorporation of supplemental phosphorus when preparing the seedbed helps promote root development.

Established Plant Material

• Grasses. Apply in the fall (early to mid-September) to promote winter survival and early spring growth.
• Wildflowers. Very low rates, if any at all. High fertility levels will stimulate spindly and weak stem growth.
• Trees and Shrubs. Apply macro-nutrients (N-P-K) early in the growing season. Late summer application could delay proper “hardening off.” Micro-nutrients are available in foliar spray. Since the safe limits for application of trace elements is narrow, they are best applied with caution. High and low soil pH can limit essential micro-nutrient availability to plants.

Caution: Overuse of fertilizers may result in the contamination of surface and ground water, and the unwise use of natural resources. Utilize a soil analysis to identify soil nutrient deficiencies and fertilize accordingly.

Pest Control

Adopt an Integrated Pest Management (IPM) approach to controlling weeds, insects, and disease. This approach incorporates monitoring to determine the level of infestation with a combination of control measures, i.e., cultural practices, pesticides, biological control, choosing plants with pest and disease resistance, maintaining good plant health (vigor), practicing good sanitation, and properly timed control methods. Cultural practices include tillage, hand-pulling of weeds or hand-plucking of insects, and mowing.

Insects

Native vegetation will probably attract more desirable insects than pests. Butterflies and other pollinators will be attracted by flowering forbs and shrubs. Conscientious use of pesticides, use of less toxic compounds (insecticidal soap, dormant oil spray, diatomaceous earth), and strategic placement of insect deterring plants should solve most insect pest problems. Monitor insect populations closely so that control measures can be implemented in the early stages of infestation.

Diseases

Sanitation is the key to disease control and prevention. With careful monitoring and early detection, most diseases can be avoided. As with insects, native plants have evolved a natural immunity to many diseases. With selective pruning, excess litter removal, and in some cases, by using fire, diseases in a natural landscape will be minimal. Also avoid late afternoon or evening watering of foliage.

Animals

Native landscaping, especially in rural and suburban areas, will at-tract potentially damaging animals (deer, rabbits, rodents, beavers). Until plants are large enough to withstand browsing, some form of plant protection may be necessary (see Plant Protection section). The planting of less palatable shrubs and trees is a feasible alternative.

Weeds

Perennial weeds should be dealt with prior to implementation of a landscape plan. Annual weeds can be reduced by not allowing them to go to seed. The first two establishment years require the most maintenance, but once your landscape plants are established maintenance becomes easier and more routine. Caution should be used when using any herbicides within the rooting zone of woody plants.

This information is also available for downloading as Chapter 13 of the publication, Creating Native Landscapes in the Northern Great Plains and Rocky Mountains. This document requires Adobe Reader.

Maintenance (PDF; 1.2 MB)

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