Nontreated manure could lead to unwanted seeds

Q: Last week, the article about spreading and turning under the mulched leaves and some manure made me wonder ... why “heat-treated” manure? My son lives in the valley and there is a stable where several horses are boarded. They free-range in a pasture every few days, and I know their manure is collected from their stalls regularly. I haven’t asked, but I’m willing to bet that some of that manure would be available and more than likely free. Couldn’t I use that when constructing a new garden bed?  — W.F., Albuquerque

A: The big reason I suggest using heat-treated manure is seed. 

When the manure is heated adequately, most seed harbored in the manure is cooked so it can’t grow. 

Sure, the manure you might get from the stables is free but do you know what the horses are consuming while hanging out in the pasture? They could be ingesting all manner of weeds and if they were in seed, that seed usually passes right through virtually unharmed and ready to grow. 

Now I’m not saying the pasture is a weedy mess, no, not at all, but along fence lines and other spots, weeds can and do pop up, making for tasty fare for grazing animals. If those weedy interlopers were wearing seed, then you’re spreading it and in turn planting it, so to speak, with the turning under with the leaf mass. That could spell trouble. 

All that weed seed could hang out until the weather is perfect and then sprout, like early next year, just as you are getting ready to garden. 

I know that the heat treatment does reduce the nutritional value of manure a smidgen but having been “cooked” there is less chance of planting anything you don’t want to grow. It’s as simple as that. 

Now if you have the space and can dedicate yourself to composting, that free manure could be cooked, making it far less a carrier of who knows what. That way you’d help the stable owners by removing some of their bumper crop of manure and make your own black gold to enrich your plantings. 

What I know about composting wouldn’t fill a thimble, but I’m confident there are instructions out there for the asking. Your county agricultural agent, the Master Gardeners, our nurseries and the internet would probably be able to offer info to easily learn everything you ever wanted to know about composting. 

But me? I’d stay away from manures that haven’t been heat-treated. I believe it is a tidier way, in the long run, to enrich the soil. 

Happy Holidays to you all and know that with the winter solstice upon us, the sun will make its way back, encouraging us to keep Diggin’ In for another year!

Fondly, Tracey.

Tracey Fitzgibbon is a certified nurseryman. Send garden-related questions to Digging In, Albuquerque Journal, 7777 Jefferson NE, Albuquerque, N.M. 87109, or to features@abqjournal.com.