Hartley Magazine

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What’s Wrong with my Plant?

Five questions for strong healthy growth

What do gardeners really want? Recently, I conducted an unscientific two-day sampling of homeowners’ gardening questions. The most common concerns were about how to help ailing plants. I spent an enjoyable weekend, volunteering in the “Ask An Expert” booth at the Sunset Celebration, a hoopla of all things great about living in the West, held on the grounds of Sunset magazine’s headquarters in Menlo Park, California. Under the tent, Sunset editor Kathy Brenzel, senior garden writer Sharon Cohoon, who edits Sunset’s blog Fresh Dirt, and an ever-changing group of extremely knowledgeable Master Gardeners had plenty of nifty answers for most questions—although there were some stumpers.

Most were about citrus, which grow outdoors in the Bay Area. My favorite was “Why does my plant have yellow leaves?” Yellow leaves in plants are like headaches in people. Without more information, the cause is anybody’s guess. As a writer, I’m more comfortable posing questions rather than answering them. That day I found myself asking about their plant care practices. A healthy plant is more impervious to ills, whether from bacteria or insects, so we’d go through my basic questions and usually hit on a cultural aspect they’d overlooked-Voila! That’s the one to try.

Here are the five diagnostic questions I used. The first four could work for any ailing plants. The last is citrus-specific, because in other parts of the country, container-grown citrus plants are terrific in greenhouses, or even sunny windows with a stint outside in summer. Plant tough-love alert – if a specimen needs more care than good culture and compost tea or insecticidal soap can provide, go ahead and chuck it. Find other varieties. The world is full of fabulous, disease-resistant plants.

Questions for diagnosis 101:

  • Are you delivering water on a regular basis? Citrus especially appreciate this. Dry soil on top signals the need for more.
  • Are you feeding regularly? I prefer a good organic plant food with low numbers (like 3-5-4 or 4-8-4). New growth is not overstimulated and tender, a condition more attractive to pests.
  • Do you mulch to cut down moisture loss? Use bark or even pebbles, but don’t tuck mulch up against the stem.
  • Is the plant potbound? Pull out and check roots—this could be a two- or three-person job with older trees.
  • Could your plant be iron deficient? Yellow leaves in citrus may be caused by a need for iron, easily remedied with specific food.