We planted our hedge of 5-6 foot cedars last fall, and many are now yellowing and turning brown in spots or large areas. When we planted, we dug 14inch deep holes, put in a topsoil mix (our soil is hard pack clay/sand/sandstone) and mixed in a cup of bone meal. The trees were left in the natural burlap sacks, without twine, and were well watered in. After planting, we trimmed the tops about 6 inches to encourage rooting (as we were told). The hedge has looked good until about 3 months ago, when some trees started to slightly yellow. Many are now quite yellow, and we've lost/are losing at least one. Our yard does have spider mites, but there weren't any problems in the first 8-9 months since planting the hedge. Please help - we're new at this and don't want to replant and repeat mistakes.
Soil probably not draining adequately, with amended planting holes acting as sumps. Dig up browning individuals and inspect roots, soil around them for moisture-related issues. To get replacements to succeed you may have to remove and replace existing soil over a fairly wide area, or plant in a raised bed; if water is puddling in the area drainage lines may even have to be installed. Next time take burlap completely away. Top pruning at planting time would actually tend to decrease root growth, plants are integrated systems (organisms) just like us. Mites and root rot both most likely to appear during hot weather. http://www.puyallup.wsu.edu/~Linda Chalker-Scott/Fact Sheets/Planting fact sheet.pdf
Thanks for your advice. Glad we found this forum now - would have been better to find it before we planted! Could the apparently inadequate drainage also be a result of overwatering? Because of the slope in our yard we may have been trying too hard to get the roots soaked during the summer. And when the yellowing started, we thought it was too dry, so we really went at it with the soaker hoses. If we dug a trench with a ditch witch right beside and filled it with drain rock, or something along those lines, could that help? Either now or with future trees. Thanks again - jen
Hi Joshjen. The rule of thumb with any plantings is that you must incorporate your garden's native soil in with the new soil you are using for the planting. If you have average or poor soil (i.e,rocky, sandy, clay, etc.), and then dig a hole and put in top soil and manure/compost, etc., you are asking for trouble. I make sure that I add at least 30% of the surrounding native soil in with the new soil in my planting hole. It's not so much that you're overwatering, but just that your new soil can't drain properly into your native soil (as Ron B said, your amended planting hole is acting as a sump), especially in heavy rainfalls and in wintertime, as water "backs up" and will in time start to rot your plant's roots. Also, your plant will most likely not send its roots into the surrounding native soil, and will end up going around in circles in your amended planting hole. That's ok with good drainage, but you'll probably end up with a smaller plant, as you'll get the same results as putting your plant into a container. Happy Gardening! Sue1
