Garden Plot: Your peas can freeze on St. Patrick’s Day – unless you cheat

Chesapeake Bay temperature a helpful hint for gardeners

wtopstaff | November 14, 2014 6:00 pm

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Editor’s Note: Mike will be speaking at the Fredericksburg Home and Garden Show this weekend. For more information, click here.

Mike McGrath,

Your peas can freeze on St. Pat’s — unless you cheat

Sunday is St. Patrick’s Day, the lucky day for planting cool-weather loving snow peas, snap peas and shelling peas in your almost-spring garden. But it won’t be very lucky if you just bury the poor pea seeds in freezing cold soil.

Although the plants thrive in cold weather, the seeds need warm soil to germinate and would rot if planted now. So cheat, and pre-sprout them inside before planting.

It’s easy-just wrap your pea seeds in moist paper towels, put the towels into plastic bags, fold the bags over loosely and leave them to sit out at room temperature. Check them daily, and after two three days, they’ll have little tails poking out.

Now you can plant them without fear of the seeds rotting in the soil — and get several extra weeks of pea picking time before summer heat burns up the vines at the end of their oh-so-short season.

Gentlemen: Get your gluten

The all natural ‘weed and feed,’ corn gluten meal is a great way to give your lawn a spring feeding and prevent crabgrass and other dormant weed seeds from sprouting — without exposing yourself and our water supplies to the hormonal disruptors in old school chemical weed and feed.

But, as with any pre-emergent, your timing must be perfect. To knock out the most weed seeds, you want to get your material down right when the soil temperature reaches, or is fast approaching, 55 degrees. (That’s as measured 4 inches down.) In the past we’ve always told people that’s when the redbuds and forsythia begin to bloom, and to look to those plants for your cue. But some people whined, “I don’t havvvveee one of those plants in my yard!”

Luckily, as I mentioned last week, Bob (a Master Gardener in Maryland) recently revealed another great new way to know where we are, soil-temp wise. He explained that the temperature of the water in the Chesapeake Bay closely mimics the soil temperature in our region. So, have your gluten in hand before that number hits 50 degrees and then spread when ready.

Using the bay to beat crabgrass

So Maria in Bowie writes: “You’ve been suggesting that we apply corn gluten meal to our lawns to prevent crabgrass when the water in the Chesapeake Bay reaches 50 degrees. Huh??? I have no idea when the Bay will hit 50 degrees. I live too far away to take its temperature!”

Ahem and harrumph.

When I explained that the temperature of the water in the bay mimics our local soil temperatures, I expected people to start checking online weather maps, which always show the water temperature.

But super-listener Paul in Bethesda in Bethesda did me one better. He sent me a link to the National Oceanographic Data Center, which shows that the water temperature this week was already up to 46 degrees. It was only 40 degrees a week ago, meaning that things are heating up fast, and you better be ready-because once crabgrass and other dormant weed seeds sprout, no type of pre-emergent herbicide will harm them.

“Pansies, Lilies, Kingcups, Daisies, Let them live upon their praises … There’s a flower that shall be mine. ‘Tis the little Celandine.”

Apparently, the beautiful buttercup-like flowers of lesser celandine, a “weed” that inspired the likes of Tolkien, C.S. Lewis and Wordsworth (who wrote the headline above), has been colonizing the sides of some streams in Rock Creek Park.

Now, lesser celandine is one of the few plants that can survive in frequently submerged/almost always wet areas like this. And it does more than just survive — it thrives, preventing the massive erosion that would otherwise occur.

So park officials are spraying it with a derivative of Roundup, an herbicide that has been shown to decimate populations of frogs and toads, especially during the breeding season.

The punch line, of course, is that this is the breeding season.

Pogo: You were right. We have met the enemy and he is us.

An easy way to insure un-weedy compost

Tom in Huntingtown writes: “I really like the idea of using compost in place of wood mulch, but the weeds were just too much when I used compost last season. The compost was generic — a bulk delivery from a local shop. I would rather use the Leafgro you recommend if you’re convinced it won’t be a nursery for weeds.”

Properly-made compost should not contain weed seeds, Tom. But sometimes, it isn’t made right. Here’s an easy way to check. Take a sample of the compost home, fill shallow containers with it, water them and wait a week. If sprouts appear, seek a new source. If no sprouts, get a big batch and spread it.

And rest assured that university studies have clearly shown that clean compost prevents weeds just as well as those nasty wood and bark mulches.

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