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Caring for your native plant wildlife sanctuary

Native plants, which evolved in this climate, in general need less maintenance than introduced plants. But any yard will quickly revert to weeds without some care. Here are some general maintenance principles for keeping your yard beautiful while supporting the wildlife that inhabit it. Institutions should create a written maintenance plan - see below for suggestions.

 

Support wildlife all winter

Seed heads feed the birds, stalks provide nesting sites for bees and shelter for birds, and dead leaves provide shelter for turtles, caterpillars, and other creatures. Therefore the ideal cleanup routine would be to leave everything alone over the winter. In the early spring, cut back the dead perennial stalks if you like, but for the sake of the bees, leave 12-18 inches of any stalks that have hollow or pithy cores. (Bees burrow into the ends of last year's dead stalks after they have broken off or been bitten off by deer. The eggs then stay there over the following winter and emerge the next spring.) Unless you have a major aesthetic objection, it is good to leave the leaves and stalks in place. Every thing will get covered up by growing plants in the spring - the perennials will poke their way right up through them, assuming you have not piled on too thick a layer of extra leaves.

A thin layer of dead leaves will not hurt the lawn. In fact, many of them will shrivel up and disappear surprisingly fast. Examples include Maple, Cherry, Ash, Willow and Elm species. (Oak and beech leaves are very slow to decompose and are more likely to smother the grass if not chopped up.) If the leaves are too thick in one area, you have several choices:

  • Add them to garden beds

  • Spread them under shrub beds

  • Spread them in the woods (but not too much! Piling them high will kill the ground layer of plants.)

  • Put them in a compost heap

  • Chop them up and leave them on the lawn by running over them a couple times with the lawnmower. (This of course risks chopping up the butterfly larvae, eggs and pupae which floated down with the leaves from the trees.)

Do the world a favor and avoid leaf blowers. The  carbon emissions are considerable, and the noise is horrific. Noise pollution is bad for humans and for songbirds and other critters which have trouble communicating over the din.

General inspection

Visiting the garden frequently will allow you to appreciate the garden as it unfolds and as birds and other wildlife move in. But, to check for problems, a monthly inspection by someone who is familiar with the plants is a good idea.

 

Water deeply until established, then stop

You should water thoroughly when planting - one way to do that is to put the plant in the hole and fill it with water, allowing it to drain before replacing the soil. Water again the next day, then twice a week for a couple weeks. After that, plan to do a deep watering once a week whenever it is needed. Over watering is problematic, so ideally you want to wait until the soil down at the roots is dry and the plant is starting to droop just a little (plants can droop from too much water, too). For perennials, keep this up until the following winter. For shrubs, give it a year.

 

For large trees, water with one gallon of water per inch of trunk caliper every other day for at least a month, then twice a week until established. Large nursery stock trees have crowns larger than the root system can support, so they need extra water until the roots catch up. Water around the edge of the planting hole to encourage roots to reach for the water. Trees become established in a year for every 1.5 inches of tree caliper. In other words, a tree with a two inch trunk will take 3 years to establish. Each year reduce the amount of water per inch by 1/n gallons, where n is the number of years to establishment.  For example a 1.5 inch caliper tree takes 3 years to establish, so in the first year it gets 1 gallon per inch, the second year it get 2/3 (1-1/3)gallons per inch, the third year it gets 1/3 (1-1/3-1/3) gallons per inch. The reduction in supplemental watering reflects the growing root system’s greater ability to absorb natural soil moisture.

 

For seedling trees, water with 1 gallon of water when planting if the soil is dry.  Then water with 1 gallon after 2 weeks without measurable rain. Water around the edge of the planting hole.  This will force the seedling to develop a good root system. Over watering will make the plant less drought tolerant.

 

Do not fertilize

Most commercial fertilizer is not only unnecessary, but at times is harmful to native plants. Adding organic matter in the form of compost or mulch will improve the soil and provide nutrients to the plants.  One simple thing to do is to keep a can in the kitchen. Put coffee grounds (including the filter paper), egg shells and vegetable parings in the can. When the can is full carefully bury the contents in your garden.  This will feed the soil microbes and release nutrients into the soil. Or make compost in a pile or a bin. Not only will you be feeding your soil, you will be reducing a substantial fraction of our waste stream.

 

Do not use insecticides

Keep in mind that native plant gardening is about creating a balanced ecosystem and so is as much about growing insects as growing plants.  Native plants and the predators of plant-eating insects have evolved mechanisms to work together to control pests. For example, some birds can smell leaves that are being fed upon by caterpillars.  You should not need any insecticides in an established native plant garden, as it would completely defeat the purpose. New gardens sometimes have an outbreak of aphids, scale or other small sucking insects.  These can be treated with a non-toxic horticultural oil that smothers the small suckers and does not harm other insects. Aphids can be washed off with a sharp squirt of water. Remember to leave some of the sucking insects to attract their predators.

 

Shade the soil

In nature, fallen leaves help hold in moisture, cool the roots, provide organic material to the soil, and provide essential shelter for insects such as overwintering caterpillars. Multiple layers of plants also perform these functions. Where leaves are absent or plants are sparse, applying an inch or so of organic mulch can be helpful. Too much mulch will prevent seeds from sprouting from your native plants and will add more organic material than these plants need. Do not let mulch touch the base of the plants! The “mulch volcanoes” that we see piled around trees kill rather than help trees.

 

Weeding

As in any garden, weeds need to be kept down. But every time you disturb the soil, more weed seeds germinate, which has led to the latest suggestion that can work for some weeds: instead of pulling up the weeds by their roots, cut them down at ground level until they give up. As the desirable plants grow, their shade will start to reduce weed growth - this is called “Green Mulch.” Note that in a native plant garden, just because you didn’t plant it doesn’t mean it doesn’t belong. Nature will sometimes add desirable and hard-to-find native plants to your garden if you let it. Ideally you want to know what a plant is before you remove it. Having said that, just because a volunteer plant is native, doesn't mean you have to keep it - it's your garden, after all, and aesthetics are important! (See this page on native garden design.)

The majority of garden weeds are non-native. The Seek app can give you a quick tentative identification and does not require you to set up an account. It relies on the iNaturalist database - the iNaturalist app will give you a more accurate list of possible identifications.

 

Replacing lawn yarrow, bee balm.jpg
Liatris spicata, Rudbeckia hirta, Phlox
Lonicera sempervirans on trellis.jpg
Woodland garden, Tiarella cordifolia, Me

Grooming

Pruning: If you choose plants whose maximum size is the right fit for your landscape, routine pruning will be unnecessary. Occasionally you may choose to prune for aesthetic reasons. For instance, cutting back Hydrangea arborescens in the late winter will result in a more compact shrub. The shrub Viburnum prunifolium can be made to look like a small tree by removing lower branches when it is young.

 

Deadheading: If you do not want a flower to go to seed, you can remove the seed head. In some cases this may promote a second wave of blooms. Plants with a tendency toward prolific reseeding that may be too much in a garden setting include Symphyotrichum, Eupatorium and Solidago species, Salvia lyrata, and Packera aurea.

 

Cutting back: Some perennials may be taller than you like and prone to flopping. Cutting late blooming plants back iaround late spring or early summer will promote bushier growth (this is called the Chelsea Chop). Doing this in stages a couple weeks apart can prolong the summer/fall bloom time. Others may benefit from being cut back after blooming to stimulate a flush of new foliage.

Some plants that can be cut back to reduce height or flopping, stagger bloom times, or create a flush of new foliage

(Click to view this as a spreadsheet)

Symphyotrichum novae-angliae New England

Did you know..

Outdoor lights contribute to the death of millions of insects and birds?

You can help:

  • Turn off lights by 10 pm

  • Use motion sensors
    Use LED lights 3000K or less
    (yellow)

Common garden weeds
(native and non-native)

Sample Management Plan for Institutions

You can make a chart with the schedule and include who will be responsible for each item and the approximate number of hours required. (For even more details and wording you can use in a contract with your yard maintenance company, see this page.)

 

At the time of planting

  • Fully engage whoever is going to be doing your lawn care and landscape maintenance. Make sure they understand the purpose of the project and can identify the plants and weeds.

  • Keep a drawing of what you have planted along with pictures and location.

  • Mark the plants with stakes. Small plugs may be hard to distinguish from weeds until they have a chance to grow.

 

Establishment phase (Years one to three)

  • General inspection monthly.

  • Monitor the property for invasive plants, and remove.

  • Watering schedule as above. Always water deeply.

  • Weed monthly during the growing season.

  • Replace mulch if needed every spring. Do not allow mulch to touch the base of trees or shrubs. Do not pile layer upon layer of mulch - keep the total layer height under six inches.

  • Mulch leaves on turf grass in the fall with a mower; leave them in place in garden beds and under shrubs and trees. Leave stalks in place as much as possible.

Spring cleanup:

  • Remove small stalks. Cut back thick stalks to 12-18 inches.

  • Leave leaves in place on garden beds unless excessively deep.

  • Edge the garden borders with shallow <2 inch deep cuts. Deeper cuts can disturb roots.

Lawn care:

  • Use a mulching mower and cut the grass at 4 inches high, leaving the clippings to feed the soil and fertilize the grass.

  • Keep fertilizer and herbicides (if used at all) away from the garden beds, trees, and shrubs.

  • Use pesticides only in case of dangerous infestations, such as a hornet nest inside a grill.

  • Carefully avoid mowing the following areas: (list here)

Control of invasive introduced plants:

(These are just some examples.)

  • Cut any English Ivy at the base of any tree where it is growing up.

  • Pull up seedlings of Autumn Olive.

  • Hand pull Oriental Bittersweet and Porcelein Berry. Where the plants are too large to hand pull, cut the vines at ground level and paint the stump with concentrated glycphosate with no surfactant (such as Rodeo). Make sure your identification is solid. Do not cut any native vines unless instructed - see this page for details.

townhouse-fall-L.jpg

Maintenance phase (Years four and after)

  • General inspection monthly.

  • Monitor the property for invasive non-native plants, and remove.

  • Do not water trees, shrubs, or garden beds unless the plants are showing signs of stress from severe drought.

  • Weed four times a year.

  • Replace mulch if needed every spring. Do not allow mulch to touch the base of trees or shrubs.

  • Rake leaves off turf grass in the fall; leave them in place in garden beds. Leave stalks in place as much as possible.

Spring cleanup:

  • Remove small stalks. Cut back thick stalks to 12-18 inches.

  • Leave leaves in place on garden beds unless excessively deep.

  • Edge the garden borders with shallow <2 inch deep cuts (deeper cuts can disturb roots).

 

Lawn care:

  • Keep fertilizer and herbicides (if used at all) away from the garden beds, trees, and shrubs.

  • Use pesticides only in case of dangerous infestations, such as a hornet nest inside a grill.

  • Carefully avoid mowing the following areas: (insert details here).

 

Special instructions for specific plants:

 

Special instructions for meadows: (An example is here.)

 

Special instructions for rain gardens: Maintaining a rain garden is very similar to maintaining any other garden.  Taking care of the plants is the same. You also need to inspect the inlet and berm for signs of erosion and correct this.  The main difference is mulching. To continue functioning, a rain garden must have an appropriate ponding depth. Repeatedly adding mulch can raise the soil level and reduce ponding depth.  Rake old mulch out of the garden before applying new mulch. Check the ponding depth every year and adjust it to the correct depth by removing soil and old mulch, then apply new mulch.

For information on building a rain garden visit: https://www.fairfaxcounty.gov/soil-water-conservation/sites/soil-water-conservation/files/assets/documents/raingardenbk.pdf

Leaf blowers

Gas powered leaf blower are highly polluting, not to mention the noise pollution they generate. Your landscape contractor is likely to be delighted if you ask them not to blow leaves off of the lawns: it will save them time and disposal fees. But they need you to want this, so they don't get complaints about their service. Watch these videos made for professionals:

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