The Native Garden, Season by Season

Any time the ground is neither frozen nor saturated. Early fall is best in most of the East: warm soil, cool air and autumn rain let roots grow before winter. Spring is second best. Midsummer planting works only if you will water.

Go easier on plants for dry ground, such as butterfly weed, aromatic aster and little bluestem: in clay, weekly watering can rot them. Water those only when the top two inches of soil are dry.

1. Mark the edge with a hose, and cut a clean edge with a spade. A crisp edge is half of looking planned.
2. Mow the grass as short as it will go, then lay plain brown cardboard over it, tape and labels removed, overlapping the pieces by about six inches.
3. Soak the cardboard, then cover it with 3 to 4 inches of shredded leaves or fine wood mulch.
4. Plant through it. In fall you can plant plugs right away by cutting an X in the cardboard. Or wait until spring, when the grass underneath has died and the cardboard has softened.

Don’t till: it wakes up years of weed seed. For a very small bed, slicing the sod off with a spade is quicker.

Plant plugs about a foot to eighteen inches apart, closer for small plants and farther for big ones. A 4 by 8 foot bed (32 square feet) takes roughly 20 to 30 plugs. The shopping list tool works out the numbers for your bed and your plants.

Prices vary, but plugs usually cost a few dollars each at plant sales, and quart or gallon pots cost several times that. Expect roughly $75 to $150 to fill a 4 by 8 foot bed with plugs. Buy a few extra: not every plug makes it.

Plant in groups of three, five or seven of one kind rather than one of everything. It looks deliberate, and bees work a patch more efficiently.

The first year, an inch or two of shredded leaves or fine mulch keeps weeds down while the plugs grow. Keep it off the plants’ stems, skip dyed mulch, and never pile mulch against a tree trunk. As the plants fill in, they become the mulch.

Leave a few sunny patches bare: most native bees nest in the ground, and they can’t dig through mulch.

Native seedlings are slow and easy to mistake for weeds. In the first year, pull only what you can name as a weed. Mark where you planted, keep the plant tags, and photograph anything you don’t recognize: the free iNaturalist or Seek apps will usually name it.

The weeds you are most likely to meet in a new bed in the Mid-Atlantic include Japanese stiltgrass, garlic mustard, hairy bittercress, crabgrass and the lawn grass you smothered. Pull these first.

• Keep a crisp edge, or a mown strip along the front of the bed.
• Put the short plants in front, and repeat the same few plants in groups.
• Add a path, a bench, a birdbath or a small “pollinator habitat” sign. It tells the neighbors someone is looking after the bed.
• If you have a homeowners’ association, read its landscaping rules before you start, and share your plan with it.

Ticks live in tall plants and leaf litter, and Lyme disease is common in northern Virginia. Wear long sleeves and pants when you work in the beds, and check yourself for ticks afterwards. A mown path lets you walk through without brushing the plants.

Wear gloves for weeding. A few native plants are poisonous if eaten or irritate skin; their plant cards say so. If you have pets that chew plants or small children, check the cards before you plant.

Plugs (small deep cells) are the best value for beds: cheap, quick to establish, and planted about a foot apart they close in by the second summer. For areas bigger than a few hundred square feet, seed is the only affordable way; see the meadow notes below and Growing from seed.

1. Clear the ground a season ahead. Smother turf and weeds under a tarp or cardboard through a growing season, or solarize in summer. Tilling brings up years of weed seed, and near a stream it may need a permit.
2. Sow in the dormant season, late fall to late winter, onto bare soil, and press it in. Many native seeds need winter's cold and wet to germinate.
3. Mow high in the first year: whenever growth reaches 12 to 18 inches, mow it back to 4 to 8 inches, so the slow natives get light.
4. From the second year, mow once in late winter, and mow only part of the meadow each year so insects wintering in the stems survive.

Expect "sleep, creep, leap": little to see in the first year, some flowers in the second, a meadow in the third.

Where deer are heavy, cage new plants for the first season. Grasses, sedges, ferns and wild indigo are rarely touched; phlox, lilies and native clematis are eaten first. Keep notes on what gets browsed. After two seasons you will know your deer better than any list.

Where you can, buy straight species grown from regional seed (a local ecotype). Named cultivars are fine in a garden bed, with two exceptions worth avoiding: double flowers, which often give pollinators little, and purple- or red-leaved forms, which in one study fed fewer caterpillars. Mt. Cuba Center's trials found that many of the best garden performers were straight species anyway.

Native plant sales are the best place to start: the plants are local and cheap, and the growers will answer your questions. In northern Virginia, the Loudoun Wildlife Conservancy’s sales at Morven Park bring several local growers together each spring and fall, and the Virginia Native Plant Society’s chapters hold their own sales. Plant NOVA Natives keeps lists of nurseries that sell only natives and upcoming native plant sales in northern Virginia. Elsewhere, your state native plant society (linked under Where you are) lists sales and nurseries.

Ask any nursery two things: where the seed came from (local is best), and whether the plants were treated with systemic insecticides, which can harm the insects you are planting for.

Never dig plants from the wild. It’s illegal on land that isn’t yours, and it drains the wild populations your garden is meant to support.

Mt. Cuba Center counts pollinators in its trial garden with a simple method: watch one plant for 60 seconds and count every insect that lands on a flower. We use it on the farm, with a few rules borrowed from the Xerces Society's bee-monitoring protocol so the counts compare fairly:

1. Count on warm days (60°F or more), with light wind and enough sun to cast a shadow, mid-morning to mid-afternoon.
2. Count bumble bees, other native bees, honey bees, butterflies, moths, flies and beetles separately. Honey bees are managed livestock; count them separately from native visitors.
3. Note how many flowers or flower heads you were watching, so a young plant isn't unfairly compared with a big clump.
4. Watch every plant you want to compare in the same session, in random order, and repeat on many days. A plant needs twenty or so watches before its number means much.

Photograph what you can't name and post it to iNaturalist or, for bumble bees, Bumble Bee Watch. Your sightings become data that researchers actually use.