When building raised garden beds, rocks are the way to roll

WASHINGTON — Christina in Silver Spring, Maryland, writes: “I’m going to build a couple of raised beds and am wondering how high to make them.

“I’d like to use stones for the frames. I’m planning to grow a variety of things and want to factor in a depth of soil that can accommodate just about anything. I just started listening a few weeks ago and am learning so much! Thanks!”

Well, thank you, Christina!

Raised beds framed with stone or pavers are an excellent idea. The stone doesn’t deteriorate like wood; and the stone absorbs heat from the sun during the day and radiates it back into the soil at night — a huge bonus for extending the season in the spring and fall.

All raised beds should be no more than 4 feet wide — so you can reach the center without ever stepping on their loose, light soil. (They can be as long as you like.)

Around a foot tall is the standard, although deeper is always better, especially if you plan to grow long-rooted crops, like full-length carrots.

Wash your deer woes away

Clemencia in Potomac, Maryland, writes: “Do you recommend Plantskydd to deter deer, evil squirrels and rabbits from eating ornamental plants and veggies? The deer especially drive me crazy. I had to fence in the garden area but want to grow some things in the rest of the yard (which has no fence). Will the activated sprinkler you always talk about scare away large deer? Even if they come in groups?”

Yes, Clemencia — a motion-activated sprinkler is the perfect deer deterrent. They’re naturally skittish animals, and their size makes them a large target for the unexpected blast of cold water that erupts when the sensor detects their movement. Some studies even suggest that deer chased frequently by a blast of noisy water will learn to avoid the area in the future.

But a motion-activated sprinkler can’t protect plants in the winter, when the water in the lines would freeze. That’s when you need protective cages or frequent applications of a spray-on deer repellent. You mention the repellent Plantskydd, which is dried blood, a slaughterhouse byproduct that creeps me out when I mix it with water. (It becomes a true “bucket of blood.”)

I prefer repellents that use rotten eggs (“putrescent egg solids”) as the active ingredient. They’re more effective and infinitely less creepy.

It’s tomato-planting time — maybe

Our ridiculously warm winter weather has many people asking if it’s safe to plant tomatoes, peppers, eggplant and such outside. The answer is yes, if you’re in the heat sink of the city or some other traditionally warm spot in our region (like near a big body of water). But caution is advised if you’re in the cooler suburbs.

The rule of thumb — and it’s a very good rule — is to wait until nighttime temperatures are reliably in the 50s to put tropical plants like tomatoes in the ground. And the forecast for outlying Frederick (which I chose at random as being kind of northern and not near the Bay), for instance, calls for temps in the 30s Sunday night and not much warmer on Monday evening. (Interestingly enough, the exact same thing happened on May 15 last year.)

Temps that close to freezing might not kill the plants outright, but can stress them so much that the harvest will be delayed by weeks. The good news is that Tuesday on out looks to be fine throughout our area. Wait those few extra days and you’ll harvest ripe tomatoes much sooner.

(If your plants are already in the ground, place cardboard boxes over them on those cold nights, making sure to remove the covers in the morning.)

Two tomatoes walk into a bar …

… Bartender turns to one and says, “Why the long vine?”

Tomato says, “It’s not my fault; I’m an heirloom!”


Getting ready to plant tomatoes? It’s important to know the two main distinctions of these popular plants.

“Determinate varieties” have shorter “days to maturity” (generally between 50 and 65, a number that’s almost always listed on the plant tag and/or catalog description) and stay fairly compact. They’re the best choice for containers, small spaces and people who want tomatoes early in the season.

“Indeterminate varieties” take a lot longer to mature — 75 to 90 days from the planting of good-sized starts in warm soil — and are the opposite of compact. The 10 to 12-foot-long vines need to be grown inside a sturdy cage of wire fencing. (Stake the cage to keep it upright; do not try and stake the actual plant.) Although these (generally huge) tomatoes make you wait until the end of summer to savor, they have the absolute best and most-complex flavors.

So, play the “Days to Maturity” game: Grow a few plants that produce tomatoes 50 to 60 days after planting, some that are rated 70 to 80 days and several that take 90 or more days to mature. That’ll give you a steady supply of tomatoes from early July until the first frost.

Tomato planting 101:

  • Don’t grow tomatoes in the same spot that tomatoes grew last year, or a soil-borne wilt may yellow them out (a problem that is guaranteed to occur in year three of planting in the same spot).
  • Dig a deep hole, pull off the lower leaves of the plant and bury most of the stem underground. Auxiliary roots will grow all along the buried stem.
  • Place the crushed shells of a dozen eggs or some other source of calcium (like crushed-up Tums or other calcium supplement) over the top of the root ball to prevent blossom end rot (the heartache of tomatoes turning black and rotting on the bottom just as they begin to ripen up).
  • Fill the hole back up with the same soil you removed. Do not improve the soil in the planting hole, or your roots will stay in that tiny little island of good soil.
  • Spread a 2-inch-thick mulch of compost — not composted manure — on the surface of the soil around your plants.
  • Do not mulch disease-prone plants like tomatoes and roses with any kind of wood or bark. With these plants, “no mulch” is better than wood mulch.
  • “Bush,” “patio” and other well-behaved determinate varieties will top out at 5 feet tall and can be contained inside a standard tomato cage.
  • Big late-season heirlooms grow on 10 to 12-foot long vines that would topple a “tomato cage” by mid-July. They must be grown inside a sturdy cage of welded wire. (Important: Do not try and support the actual vine — unless you have 12-foot-long arms.)

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