6 Softwood Cuttings to Take in August to Multiply Your Garden for Free

Plants that cost real money in spring can be had for nothing in late summer. August still offers usable softwood on plenty of shrubs and tender perennials, and six of them root easily enough for a first try.

Softwood is the current season's growth, judged by bending a stem until it breaks. A clean snap means it is ready. Anything that folds over without breaking is still too green. Anything that refuses to bend has gone woody. Most propagation advice points at June, and by August much of it has firmed toward semi-ripe. Plants that pushed a second flush after their first bloom still carry plenty of soft tips.

Rooting plant cuttings this late has one advantage: warmth. Plant cuttings that would have needed a heat mat in spring are ready to thrive now. Sharpen up your favorite pruners (we love the Corona sharpener from Amazon) and get snipping!

Cuttings to Take in August

Work in the morning while the stems are still full of water. A cutting wants to be around 4 inches (10cm) long, cut just below a node, with the lower leaves stripped. Use something sharp; crushed stems rot rather than root. Straight potting soil holds too much water, so half perlite from The Home Depot mixed through it drains better.

Two things need checking first. Patented cultivars cannot legally be propagated without a license, even at home. US plant patents run 20 years from filing, so anything long-established is free and clear. It's mostly the recent introductions — the branded reblooming hydrangeas, the newer coleus and calibrachoa series — where the tag matters. Enforcement targets commercial growers rather than private gardens, though the tag is worth a look.

Noxious weed listings are the second. Oregon prohibits propagating butterfly bush outright, and Washington quarantines it except for approved sterile cultivars.

1. Hydrangea

Hydrangeas (Hydrangea macrophylla) root so readily that gardeners end up with spares. Choose a shoot that is not flowering, since blooming stems put their energy elsewhere. Cut the remaining leaves in half across the width. The hydrangea cutting loses less water that way and still photosynthesizes. Roots usually show inside three or four weeks. Pot them before winter and keep first-year plants sheltered, because young roots feel the cold more than the parent does. Panicle types respond just as willingly.

2. Butterfly Bush

Free plants are close to a guarantee. Butterfly bush (Buddleja davidii) strikes from softwood at almost any point in the season. Rooted cuttings put on real size in year one. Use 5-inch (13cm) tips from this year's wood, and roots come inside a month without hormone or bottom heat. Wood from a shrub hard-pruned in spring does best.

3. Lavender

Lavender (Lavandula angustifolia) sits at the edge of softwood by August, so the snap test earns its keep. Strip the bottom two-thirds of leaves and dip the cut end in Take Root rooting hormone from Amazon, which lifts the strike rate noticeably on woody-stemmed herbs. Keep the medium barely damp. Lavender rots faster than it dries. That reverses the usual advice about never letting anything wilt.

4. Rosemary

A glass of water on a windowsill will root rosemary (Salvia rosmarinus), though those roots come out brittle and resent transplanting. Perlite gives a sturdier result. Use 4-inch (10cm) tips, then allow four to six weeks, since rosemary moves slower than most. What comes out is a plant that costs nothing and moves indoors ahead of frost.

5. Pelargonium

Bedding geraniums are not geraniums at all. Pelargonium (Pelargonium x hortorum) stays soft into August when the shrubs have hardened off. Tips strike in three to six weeks. Skip the hormone and let the cut end dry for a few hours first, because these rot more readily than they fail. Anyone in a cold zone gets the most from this one — rooted cuttings take far less windowsill space than the whole plant.

6. Coleus

Nothing about coleus (Coleus scutellarioides) is difficult. A snapped stem left in a jar of water throws roots in under a week. The leaf patterns hold true. Pinching the growing tip while cuttings come off makes the parent branch instead of stretching. Bring the rooted ones in before nights drop below 50F (10C). Stock plants will be waiting come spring.

Getting Cuttings to Root

Humidity is the whole game in August. A cutting has no roots. It keeps losing water through its leaves, so the air has to stay near saturated for two weeks. A seed starter tray with a humidity dome from Walmart handles that cheaply. A clear bag propped over a pot on sticks does the same job for free. Pelargonium is the exception, since it rots under cover.

Bright shade beats sun here. August light through a dome cooks cuttings fast, so the north side of a building or a spot under a tree suits better.

Test roots with a gentle tug rather than lifting anything out. Resistance means roots. Once they hold, open the dome wider each day for a week. A cutting moved straight into open air will wilt hard. Pot them up somewhere sheltered.

Next spring's garden will have cost a few afternoons and nothing else!