Local source for worm castings?

Asked June 16, 2020, 7:04 PM EDT

Hi, I'm curious about adding some worm castings or "worm tea" to my new (this year) raised bed planters. If I understand correctly, buying worm castings in sealed plastic bags could mean that the microbial life has died off. Is this true? If so, can you recommend a local source to buy from? I'm in Lansing. Thanks for your time. Best, Bill

Ingham County Michigan

3 Responses

Adding worm castings can improve the organic matter component of your soil, which is great. The living component/microbial part is a bit harder to amend because the microbes often need specific conditions to thrive. Usually the sealed bags will have some type of labeling saying the worm castings have been pasteurized, which means they should be free of living microbes. This can be good because sometimes adding non-beneficial microbes (it's hard to be entirely sure what the make up is in a non-pasteurized bag) can negatively impact your plants.

If you are trying to amend the living part of your soil, there are a few management strategies you can focus on. Read about them here: https://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/mgnt/

If you are looking for local places t o purchase worm castings, you can use the Business Directory from the Michigan Nursery and Landscape Association and search via zip code. You should be able to find some at garden centers and landscape supply retailers: http://www.plantmichigangreen.com/aws/MNLA/pt/sp/find_professional

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Thanks Isabel!

I'll look check out the links you sent.

I was curious about upping the microbial activity because I understand that it might help plants to take up nutrients better. I have 2 (out of 10) tomato plants that have begun to curl their leaves upward and the overall color is a yellowish green. The leaves are also becoming very thin. My other plants look great. I think I may have been over watering a bit and then we got a lot of rain. I've backed off for the last 5 days. They are on a driveway that gets sun for about 11 - 12 hours. It gets pretty hot. They are in sub irrigated pots with excellent drainage. I've been making sure the reservoir is full. Both plants still seem to be growing 1" - 2" a day. I don't think there should be a nitrogen deficiency, but I haven't actually done a soil test. Does this sound like something fungal or viral? I don't see the curly top type of chaos going on. The curling is fairly uniform. I understand that it could be a response to the heat, but the yellowing concerns me.

Thanks again for your time!


Great! Microbial activity can help with soil health, but if you are wondering about nutrients I would definitely get a soil test. You can start that process here: https://homesoiltest.msu.edu/

Microbial activity is difficult to immediately change. In the link I sent from NRCS you can read about management strategies you can implement over the years in your garden to help build the soil. It is a process, but a worthwhile one if soil health is something you want to focus on. Another option in raised beds is using cover crops to keep the soil from being bare in the off-season. Many people associate cover crops with larger, in-ground spaces, but you can use them in raised beds and planters as well.

I don't think the yellowing of your tomatoes is worrisome. Yellowing and leaf curl are often a sign of an abiotic (non-living) problem like heat, over/under watering or possibly a nutrient deficiency (a soil test can help you with this for sure.) It's also natural for some leaves to turn yellow as resources are being sent to new growth or producing flowers/fruit. I would only start to suspect disease if you see any sort of spotting on the leaves. You can read more about common tomato diseases in the garden here: https://www.canr.msu.edu/uploads/files/E3170_-_Tomato_Diseases_in_the_Home_Garden.pdf

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