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Wellfield Fall Turf Practices, Part 5 of 5: Compost Tea

The last step in Wellfield’s fall turf management program is the application of compost tea to turf and flower beds. If you are interested, there are a lot of articles describing what it is, why you would use it, and the brewing methods available. We’ve been using compost tea for the last few years at Wellfield, and we are still in the early stages of measuring its effects on our gardens.

Compost tea is controversial topic. Some people swear by it, while others think it is merely snake oil. The answer at this point, according to the scientific literature…the jury is still out on this one. When you read up on this topic, I would encourage you to consider the source. There are a number of reasons for the uncertainty, such as different food stocks, starting inoculate, and the use of different quality soils or potting media. The bottom line: we are still learning quite a lot about the efficacy of teas, what situations in which to use it, and which species respond the best.

I am going to skip the ins and outs of this debate and provide a quick explanation of the reason I apply teas and how and when. First let me say, compost tea is NOT a replacement for compost and should not be utilized as a fertilizer. The most important thing you can do to feed your turf soil is to regularly apply compost, as discussed last week. Wellfield staff currently apply compost tea to turf and flower beds alike to inoculate and boost populations of the beneficial microbes so critical to healthy plants. Compost teas show some ability to suppress some diseases and improve the quality of some plant material. The compost we spread has some diversity of beneficial microbial populations, as we apply tea brewed from an organic compost source other than what we already apply, which potentially increases the diversity, and thus the resiliency of, the soil ecosystem.

Compost tea is applied at a ratio of 10:1 using a tank sprayer. We apply it, along with our liquid fertilizer, to annuals weekly for the first half of the growing season, backing off to every other week through the beginning of September. Every other growing space at Wellfield gets two doses per year. This will be the end of the third year of two applications per season. In the future, we might reduce the application frequency for established gardens and monitor the results. Either way, the value of compost tea is hard to measure and tends to be indirect. My goal is to feed the soil through multiple methods, creating a robust, resilient soil ecosystem, because what is not in doubt is a healthy soil equals a healthy turf stand, and for now, I believe compost tea is a key component in this process.

Josh Steffen
Horticulture Manager

Note: If you missed any of the first 4 installments of Josh’s Fall Turf Series, click these links to read them!

Part 1: Core Aeration

Part 2: Compost Topdressing

Part 3: Seeding

Part 4: Organic Granular Fertilizer

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