Here are some questions I encountered this past week.
Q: How do I get rid of the leafcutter bees ruining my roses?
A: It's a beneficial insect, taking moon-shaped pieces from plants to make her nest to lay eggs and fill with pollen. Next season, the hatching larvae feed on the pollen until ready to emerge. The bee is hard to kill because of the way it operates. It has pinchers that clamp onto the leaf, and then a scissor-type apparatus makes a clean cut. I consider the missing chunks a decorative addition to my plants and my offering to propagating plants.
Q: How do I kill mushrooms in my roses?
A: Since it takes a refined eye to determine if they are poisonous, get rid of them, but removing them won't correct your situation. Mushrooms are fruits of soil fungi that are breaking down nutrients for your plants. Overwatering with too much decaying organic matter present may cause them to pop up again. Allow the soil to dry out between waterings. Another reason to destroy them is that poisonous mushrooms can be dangerous to your pets.
Q: How can I groom my scorched houseplant leaves that dried out while vacationing?
A: To keep them looking natural, trim along the leaf edges, removing the damaged tissue with sharp scissors and follow the same curves of the leaves. When going on your next vacation, group plants in the shower to reduce water loss and raise the humidity.
Q: Are we supposed to skin palm trunks?
A: If you feel you must, do it. Use a linoleum knife and start at the base of the tree by making quarter-inch deep cuts into the trunk around the plant. The broad bases of the old leaf stalks come off with a slight tug. Keep cutting around the trunk but a little higher each time until the underlying trunk becomes light tan. If you continue removing the stalks, you'll expose the palm's heart and may kill it.
Q: Our gardener planted a 24-inch boxed mesquite tree but only removed the top half of the box sides. Do we need to remove the rest of the box?
A: It's best to remove all the sides, but you don't need to remove the bottom of the box. You run the risk of damaging the root ball. Plus, most roots are in the top 18 inches of the soil. Any anchoring roots will grow through it as it decomposes.
Q: My neighbor's tree roots are destroying our block wall. How do we handle this mess?
A: Explain to him that he can correct the invasion by trenching down his side of the fence to sever the roots coming your way. Place a root barrier (sold by nurseries) vertically in the trench and refill it. If done right, the now-buried barrier won't be visible. If diplomacy doesn't work, see a lawyer.
Q: Why are my potted herbs dying? I water them every day.
A: It sounds like your pots do not have any drainage holes, so drill some. Never let plants stand in water. Cover the drainage hole with screen to prevent the soil from washing away and to keep out those crawling critters. Water plants only when the soil feels dry an inch down, and irrigate them until the water comes out the drainage hole. Protect the sides of containers from direct sun to avoid overheating the roots. Herbs do not need much fertilizer, but it does wash away with frequent waterings.
Q: Why are my grapes dropping?
A: Grapes drop when exposed to persistent winds that cause dehydration.
Q: Why won't my cat's-claw attach to the wall? I water it every day.
A: Stop watering so much. Excessive lushness causes such rapid growth, the claws can't attach securely to the wall.
Linn Mills writes a garden column each Sunday. You can reach him at linn.mills@ springspreserve.org or call him at 822-7754.