Growers Talk

Roger McGaughey

Some years ago I met, by phone, a fellow grower from Missouri. We started talking and hit it off immediately because we had one common goal—our roots must be white. I’m not sure which of us came up with the phrase, but our motto became “White Roots Rule.” With a good root system, growing a quality plant is much easier and much less stressful. Over time, we talked about how to achieve this. We used to send each other photos of our roots and had an ongoing competition for the whitest roots on similar crops. When we finally met in person, we laughed about how our friendship started, but we still have the same opinion—we need the whitest roots possible to produce good quality plants.

How’s this achievable? Recently, I had the opportunity to attend a talk on root and stem diseases and their control at the winter meeting of the Connecticut Greenhouse Growers Association. This was a good refresher course on the main diseases, notably pythium, rhizoctonia, phytophthora, and thelaviopsis, and their chemical methods of control. However, I feel it’s also important to go back to the basics of good plant production with sound cultural techniques. Good watering practices avoid soil compaction and, together with regular soil testing, help ensure optimum cultural conditions.

Whichever type of soil mix we purchase, it’s useless unless we keep it loose and open. When we fill pots ahead of planting and stack them on top of one another, we’re starting the compaction process. As we wet the pots, stage two of compaction begins. Overwatering, especially early on, can ruin the soil structure, deplete it of oxygen, and make it difficult for young roots to penetrate the mix.

Watering is an art, and we can’t do it all ourselves, so we need to convey to our hosepipe holders what the requirements of the job are. Initially, after planting, I like to water lightly. By that, I mean wetting the top inch or two of a pot—not just flashing water over the surface. It’s important to have good water pressure in the system, but that doesn’t mean the tap has to be turned on fully with the valve wide open. Also, if some of the holes in the nozzle are blocked up, the tender plants can be beaten into the compost by the resultant force. Personally, I like to use a red Dramm nozzle with two shutoffs controlling the water pressure. The shutoff closest to the nozzle is wide open, and the one closest to the hose controls the pressure. This compensates for the valve at the water source being open too much, and the nozzle seems to work better with a full flow of water. A uniform watering job helps achieve a uniform crop; so even though watering can be boring, keep focused and don’t get distracted.

As the crop grows, check the roots of your crops on a regular basis. By doing this, hopefully we won’t get too many surprises, and with a bit of luck we’ll get a lot of reassurance that our crops are enjoying their surroundings and growing happily. Regular soil testing is also important. Checking the pH and E.C. and monitoring the crop’s progress enables us to make better decisions on future feed requirements. What are we doing when we take a soil test? Right—you got it—checking our roots!

It’s a pity good cultural techniques don’t solve all the problems. Some we inherit, like fungus gnats, and we have to use chemicals to combat these insects and the root diseases they can carry and spread. I have zero tolerance for the number of fungus gnats on yellow cards—one is too many! To this end, I’m using Distance and Subdue; I get a lot of mileage out of these, especially in the early stages of production. I’m also currently trying the biological approach and trialing extensively with PlantShield. Zero REI is considerably better than 12 hours. So far, I’m excited about the results. Growers have success with many different approaches, and each of us has to find the combination that works best for us.

Roger McGaughey, head grower at Michael’s Greenhouse in Cheshire, Connecticut, was educated in Northern Ireland and England and has 34 years experience as a grower.