This publication identifies the types of injury caused by cold weather, the factors that influence the degree of injury, and ways to prevent or reduce injury. Tables are included listing the symptoms of freezing injury on some vegetables, frost resistance of annual flowers, floral development stages for fruit crops, critical temperatures for flower bud kill, critical temperatures and cold injury evaluations for small fruit crops, application precipitation rates, and row covers and frost protection. An illustration is also included showing the USDA hardiness zones of the United States.
Q. My question is, can pine needles be used to mulch rhubarb? I’ve heard that rhubarb and walnut trees don’t mix, but would pine needles hurt rhubarb? I’m afraid to let anyone put bark mulch around my rhubarb because the companies providing the bark do not know if there is walnut in the mix. – M.S. A. Pine needles should be fine to use around rhubarb, a 2-3 inch layer would do nicely. Stick with […]
Q. I lost every one of my rhubarb plants late last summer and fall. The plants started dying at one end of the row and just worked on down the row to the opposite end. Someone told me it was due to grubs; another told me that it was moles eating the grubs. Since this is a plant I intend to eat, whatever I use needs to be food safe. A. It is unlikely that […]
Q. The last couple of springs we have had this beautiful flower in our bed, with a nodding, bell-shaped bloom checkered with dark maroon and creamy white. We didn’t plant it, and there is only one. Can you tell us what it is, and where we can buy more? A. That would be Fritillaria meleagris, commonly known as the checkered lily or guinea-hen flower. This dainty spring-flowering bulb reaches just 8-12 inches tall, thrives in […]
Q. I have two hydrangeas. One is a small bush (Annabelle) about 6 years old. It is on the south side of the house but is in deep shade in summer due to large trees growing south and east of it. The other is a climbing hydrangea on the east side and is in the sun in the morning. The climber grows luxuriantly. The bush isn’t really that happy. Neither has ever bloomed. I have […]
Q. I am a resident of Orange County, just outside of Paoli. I recently noticed that my red horse chestnut tree, which had previously lost all of its leaves due to drought, has sprouted several red flowers. Some leaves are coming out and MANY buds are swelling. Many buds are not swelling, and I hope they stay that way. The drought tricked the tree into early dormancy, and now the recent rains have awakened the tree […]
Q. I have a weed in my garden that I can’t get rid of. It lies close to the ground and spreads. It has small green leaves that are thick and feel like rubber. Is there anything you can tell me to help me get rid of it? Thank you. – Sheila Denton, via e-mail A. It could be a number of weeds but sounds most like purslane. Purslane thrives in hot, dry weather. The […]
Q. I have some yucca that has turned yellow and has little black bugs on it. What can I do? It starts out green, then turns in the middle of summer. – Grace Griffin, Memphis, Ind. A. The yucca plant bug is a small blue-black bug with a reddish head. The adults and nymphs hurt the leaves by sucking the plant sap, causing the leaves to turn yellow and stippled. Treat with insecticidal soap, horticultural […]