Q: Could you tell me why the needles on our Scotch pine are turning very yellow-brown in the last couple of weeks? We live on a farmstead by Gardner, N.D. I also noticed many pines along 19th Avenue North in Fargo are doing the same thing. Is there anything I can do for it? — Shirley H.
A: This is a normal cycle of needle drop and is highly visible across the region, based on the high number of questions I’ve received. This process of nature often causes alarm when evergreen trees start to shed inner needles.
Although most conifer trees are considered to be "evergreen," their needles don't live forever. What makes them evergreen is that their foliage persists more than one year before falling. Since new needles are added every year, there is always an overlap between green needles and those that are due to fall.
Older needles on the inside of evergreen trees are shed each fall after they turn yellow, brown or reddish tan in color. Sometimes this natural process is very subtle and goes unnoticed because only the innermost needles are affected. Scotch pine trees hold their needles for two to four years. Spruce trees also cycle their needles out in the course of two to three years.
As long as the needles on the exterior of the branch tips are green, the tree is just following its natural course, and there’s no action needed. Purdue Extension indicates that environmental factors can amplify and influence this cycle as well, such as stress from drought, soil compaction or excessive moisture. This summer’s long stretches of heat might be a factor in increased needle shed.
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Q: I read with interest your article on how to winter geraniums. Mine are about 25 years old and are getting lanky. I've kept them in our cabin at 40 degrees in a sunny window over the winters. The stems are thick, so would I still get new growth if I did cut them back to 3 inches above the soil and repot, as you suggested with younger plants? One was given to me from a friend at North Dakota State University and are double-blossomed so are special to me. — Polly W.
A: I ought to hold a contest for the oldest geranium. Older geraniums like yours develop thick, often woody stems, which can become lanky, as you mention. The best way to develop younger branches lower on the plant is to cut the older branches back severely, which forces new sprouts to emerge from below. Three inches above soil line is a good target point.
Although geraniums can be left as-is for many years, older woody stems can be susceptible to rot. Sometimes they’ll bloom more profusely on fresh, vigorous, rejuvenated branches.
I would give the odds of cutback success at 99%. Because there’s always a slight chance of mishap, when I’m cutting back an old geranium with sentimental value, I take cuttings from the branch tips, and root in a mixture of half sand, half peat moss, as added insurance of the plant’s survival. Rooted cuttings are part and parcel of the mother plant, so you’re not in effect losing the original plant.
Q: I’m in the process of selling my parents’ home and there’s a beautiful fernleaf peony that I gave them that I would like to transplant to my home. Can I still do that and will it survive the winter? What extra measures should I do to protect it at this time of the year? — Jackie D.
A: You are in luck. September is the preferred time of year to dig, divide or move all peonies, including fernleaf peonies.
Water well after transplanting and there really is no other care needed because they are fully winter hardy and this is the right time to move them. Around Nov. 1 you could add 12-18 inches of leaves or straw over the plants if you’d like added insurance, just in case we get a severe winter with little insulating snow. Remove mulch in early April.
If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at email@example.com or call 701-241-5707. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.