Can a Rose be Two-Faced?

How can a rose suddenly change color? Mike McGrath, host of You Bet Your Garden, will explain how a prized plant can present a very different face; and tell the battle-torn tale of the world’s most amazing rose. Plus answers to all your growing questions.

Questions of the Week:

“My “Peace” rose was negatively affected by the cold bitter winter, but it did come back and is looking healthy. The problem is that it is no longer a Peace rose. It is now a “red” rose. What happened and what can I do about it? “

— Sharon in Allentown, PA

Tips and tricks for growing roses »

Highlights from show for June 19, 2015:

Dwarf Holly Dilemma

Susan in Germantown, Philadelphia may have lost her Dwarf Burford Holly. She gave it Holly Tone once a year, and paid close attention to it for several years, but this spring, she looked outside to find that the leaves were brown, instead of its usual dark green. Mike mentions a caterpillar pest that can turn the leaves brown, but it’s unlikely that she has that, as she would have seen chewed leaves on that plant, and it would have easily migrated to one of her other holly plants. It’s more likely that there’s something wrong with the conditions in which the plant is growing. Now, Susan uses wood mulch, which Mike says raises the pH of the soil, and might be the culprit here. He recommends that she get rid of that wood mulch and replace it with peat moss, then cover that over with compost, then prune it back by six inches to a foot. “Make sure that it gets water during any dry stretches that come, and we’ll know where we are at the end of the season.”

Over-Mulching

David from Long Island is an arborist with a public service announcement about over-mulching. He says that in addition to covering the roots with mulch, it’s also bad to leave the cages on the root balls of these plants. Mike asks if it’s possible to save these trees, and David says that while in some cases these trees cannot be saved, he has been able to cut the cages off with bolt cutters, after unearthing it with an air spade, a cool little tool that excavates soil using pressurized air. Many say that after a few years, the burlap will rot away, but due to the anaerobic environment underground, the burlap stays intact, further suffocating the plant roots. “I used to think that landscapers were just misinformed, but we recently had a guest who postulated that you can plant a lot of trees really quickly and move on to the next house and the next paycheck if you do don’t unwrap them.” David agrees and says that you can also charge more for your services if you put down more mulch. This explains the prevalence of a style of mulching known as “volcano mulching,” where the mulch is piled high around the tree trunk roughly in the shape of a volcano. This suffocates the roots and can kill the tree as the trunk grows. “If you can’t see the root flare of your tree, your tree isn’t going to prosper.”

Bay Laurels

Tajka hails from Ljubljana, Slovenia, and she has a fifty-year-old bay laurel tree which has fallen on hard times. She has consulted tree experts, who tell her that it’s time to cut the tree down. The bay laurel is a warm weather tree, which thrives in her backyard: new sprouts grow like weeds! A while back, the original tree has been fighting a scale insect infestation for many years, which does not affect the young sprouts, but they have been affected by her most recent problem: a sort of floppiness in new growth and an early loss of leaves. She had a dry, cold winter, though the ground didn’t freeze, and because none of the other plants in her garden are affected by this new problem, it is unlikely to have affected the tree. Tajka also says that other laurels in the neighborhood are experiencing scale, but they deal with it by cutting the trees down and planting new, but she wants to keep this tree for as long as possible. Now, last year, she gave the tree some manure, which Mike advises her not to repeat. Instead, he tells her to go and get potting soil, and then scour the area for the biggest, healthiest specimens of these volunteer bay laurels, pot up four of them, and then keep them safe. Take them inside in the winter, and put them out in the sun in the summer. As for the big tree, he recommends putting out suet feeders all around the tree to attract carnivorous birds who will eat the scale. Meanwhile, once these youngsters are a good enough size, cut down the old tree and put one of these new trees in. “I’m happy that you have these baby bay laurels around, because these young plants, like our kids, are the future.”

Browning Hedges

Glenn from Clayton, NJ planted leyland cyprus to form a hedge years ago, but there’s a lot of browning going on. Last year, he used a fungicide known as Kocide 2000, which Mike notes sounds pretty scary. Mike also tells him that fungal infections don’t turn plants brown. Now, this browning is only occurring on the inside and is not visible from a distance. Glenn says that these plants are growing near a treated lawn, and used to be mulched, but no longer are. Glenn also feeds them with 10-10-10, for which Mike admonishes him. “No plant wants an equal amount of the three basic fertilizers. There is not a single plant on the planet that that is a balanced ratio of.” Since they are growing near a lawn that’s being treated with chemical salts, these plants, which are already stressed, don’t need even more chemical salts in their systems. He also mentions that lawns don’t really need any herbicides in order to grow properly, and that the cyprus may be too far gone, mentioning persistent herbicides that work very hard to kill all plants, including the ones you want to grow. He also says that the insides of the trees aren’t getting enough sun, so he recommends planting a second line spaced further apart in case the first line doesn’t make it. “Sun is everything.”

Silver Maples

Kaye from Dayton, OH recently moved into a new house, which has two silver maples growing in her yard, and the one in the back didn’t leaf out until much later than the one in front. It did drop a lot of seeds, but when the leaves did finally come in, they came in very small. Mike says that there are a couple reasons why trees drop lots of seeds. They do it either when they’re very happy, which is unlikely here, or it could happen as part of a cycle, or, the most likely in this case, when trees are under serious stress and may be heading towards death. Silver maples are very “trashy” trees. They grow fast, they’re brittle, and they aren’t very long-lived. Kaye has a lot of plantings around the base of the tree, which Mike advises she remove, uncovering the root flare. Then, in a ring around the tree, extending about six feet, put down a layer of compost. If this tree has to come down, Mike advises that she take down the other one around the same time, as it probably won’t last much longer than the one in back. “Start saving quarters in a jar, honey.”

Ants in Potted Plants

Pamela from Edmond, OK has ants living in her plant pots and she wants to know what to do. Mike says that she doesn’t need to go as far as replacing the soil, and that the ants are just living in there because the soil down in Oklahoma is so poor and hard to live in, and so the ants prefer to live in the light, moist soil in the pots. Mike has two methods for getting rid of ants, and one is to flush the pots with water. Typically he wouldn’t recommend this, but because of where she lives, and because of the hot, dry, summer they’ve been having, she can really saturate the soil, even keeping saucers underneath the pots. Let the water sit for about an hour before draining. The other solution is boric acid ant traps, which can be found in most hardware stores or garden stores. These are premade traps, composed mostly of sugar with just a bit of boric acid in it. He recommends to put a little bit of the solution on a piece of cardboard, or just set the trap down on top of the soil, then put a towel around the top of the container to keep bees from getting into it. Since the solution contains very little boric acid, the ants won’t get sick for a few days, but will have brought some back to the colony, poisoning the queen and bringing the colony to its proverbial knees. The solution is safe for humans, having been used to clean babies eyes and mouths. It is only harmful to ants. “Don’t get anything that’s a jumble of letters and numbers ’cause that would be a chemical insecticide and you just don’t need it in this case.”