How to tell if trees, shrubs and perennials are dead or just slow
Gardening columnist Don Kinzler offers advice on telling whether perennial flowers, deciduous shrubs, evergreens, trees, lawns and more are dead or simply growing slowly due to the late spring.
Do you know the easiest way to stop a dog from digging in your garden? Take away his shovel.
Digging dogs aren’t the only cause of plant problems; winter can be tough on plants, too. And of course, there’s rabbits.
How do you tell if perennial flowers, trees or brown lawn spots are dead, or just slow to grow, especially when spring has been slow to arrive? Let’s take a walk around the yard to investigate.
- Patience is the key. Some types begin growing early while soil is still cool, like bleeding heart and peony. Other perennials are almost always slow to emerge, like hosta.
- Older, established perennials with larger root systems usually begin spring growth before last year’s new plantings of the same type. Younger plants are often slower to emerge than well-established plants.
- Plants in sheltered, warm microclimates advance quicker, like those planted on the sunny south side of a house foundation.
- If a perennial is lagging behind, check for life by gently brushing away soil near the plant’s crown, which is the area near soil level where new shoots arise. Look for swollen, soon-to-emerge buds, which might be white, pink or green. If no buds are visible, squeeze the crown tissue. If it’s squishy and feels rotten, the plant is probably dead. If the crown is firm, there’s still hope.
- Many perennials might look lifeless but are simply slow to emerge. If the crown seems solid, some types can take until June to emerge.
- Speed of spring growth varies greatly by type. Many spireas are slow to leaf out, while forsythias burst into bloom early, even before foliage forms.
- If questioning a shrub’s condition, give the "thumbnail test" by scratching twigs. Live twigs have a thin green layer, the cambium, between the outer gray or brown bark and inner white wood. If the green layer is absent or brown, the twig or branch is likely dead. Live twigs are more pliable, while dead twigs are brittle.
- If a shrub is suspected to be dead, wait to see if growth arises from the base. Even though the upper branches might have been winter-injured, many shrubs will regrow nicely from near ground level, after which dead branch portions can be pruned away.
- If rabbits chewed away the outer bark, exposing the inner white wood, the portions above will likely die if the injury encircles the branch. Prune to a point below the rabbit injury, or for a good rejuvenation, prune back all branches to six inches above ground level, and most deciduous shrubs will regrow nicely from the base.
- Both tree and shrub evergreens are susceptible to winter burn. Sometimes foliage is brown and brittle, but the twigs remain alive, ready to sprout fresh growth. Check for sappy, plump buds at twig tips. If twigs are crisp instead of pliable, and buds are paper-dry, the branch or plant might be dead.
- If burning hasn’t killed large sections, smaller damaged areas might be successfully pruned. Wait until June to determine if, and where, regrowth occurs.
- When rabbits consume evergreen foliage, leaving old woody, bare internal branches, they don’t often sprout new growth, and leaving them permanently bare.
- If rabbits have consumed the bark of evergreen trunks or branches, there are no remedies that will replace the conductive tissue that’s been eaten away. Wait and see is about the only option.
- Species vary greatly in earliness of spring budding. Oak, linden and ash are among the last to leaf.
- If wondering whether a tree or branch is alive, give twigs the scratch test mentioned in shrubs.
- If rabbits have chewed bark from around the trunk or main branches of fruit trees, there are no sealers, paints or wraps that will replace the conductive tissue that’s been lost. Trees will sometimes leaf out, but might quickly decline from the damaged tissue.
Brown patches in lawn or damage from voles
- Rake dead grass and look closely for green shoots sprouting at soil level, which should appear by mid- to late May if grass crowns are alive.
- Flush dog-spots with ample water.
- Reseed areas where no green activity is visible.
Asparagus, rhubarb, strawberries
- Check the crown area at ground level for small signs of new buds.
- If no buds are visible, feel the crown for live firmness versus squishy rot.