Though the math isn’t done yet, this spring likely has been one for the record books. The list of landscape woes keeps getting longer, from last fall’s polar plunge to the not-so-merry month of May’s hail and floods, to this month’s plague of flea beetles. Other insect pests have arrived, weeds are beyond prolific, and fireblight and leaf spot are rampant: The upside: low water bills, more planting opportunities — and green fields and foothills.
TOMATOES, OTHER VEGETABLES
• Make sure indeterminate tomato varieties (the ones that keep growing and producing until frost) are well supported with sturdy plant cages. Place cages at planting time so there’s no chance of disturbing the root balls. Be sure to disinfect the cages or plant supports that you’ve used before with a 10-percent bleach solution or Lysol to eradicate any disease from last year. Just spray them far away from plants or lawn areas.
• Tomatoes and other warm-season vegetables and herbs (basil, eggplant, peppers, tomatillos, okra, corn, cucumbers, squash, melon) like 70 to 95 degrees during the day and over 55 degrees at night, so plant accordingly.
• With some exceptions, early to mid-June is the deadline for planting such crops for them to have the needed 65 to 80 days before harvest. The exceptions: Basil can be direct-seeded through mid-August. Bush beans, slicing cucumbers, okra, New Zealand spinach, summer squash, parsley and cilantro can be direct-seeded until mid-July.
• Try planting in containers if your in-ground conditions aren’t cooperating. Most vegetables grow well in containers as long as they are located correctly for sun or partial sun, large enough to handle the plant size and receive regular water and fertilizer. More:
WEATHER WISDOM
Here’s why growing vegetables can be so bewildering in Colorado: There are three distinct growing and planting seasons, and they exist outside the arbitrary calendar dates for those seasons. They are spring (March to mid-May), summer (usually mid-May to mid-June) and fall (mid-July to August, except for garlic, which can be planted in September or October for a harvest the following spring). To complicate matters, there is overlap between these seasons.
• Spring crops, also called cool-season crops, are planted weeks before and up to the last average frost date in May. They prefer cooler daytime temperatures of 60 to 80 degrees days and tolerate cool nights down to the 40s. They appreciate frost covers or cold frames if nights hit the low 40s to 30s. Popular spring crops include lettuce, spinach, broccoli, carrots, peas, parsley, beets, potatoes and onions. The goal is to plant and harvest them before warm temperatures (above 80 degrees) set in for the summer. The exceptions are the longer-maturing potatoes, turnips, parsnips and onions, which are usually harvested in late July (potatoes) or later into the fall (turnips).
• Because of the rainy spring, a lot of gardens have been too wet to plant or direct-seed cool season vegetables. It’s a problem that raised beds can help you avoid, at least somewhat. If you used or are using containers, tunnels or a system to keep the soil relatively dry, then count yourself lucky and share the harvest.
• Many cool-season vegetables, especially those that grow quickly, get a do-over in fall, and you can start planting them in mid-July to early August. Just pay attention to the seed packages to make sure they have time to mature before the average first fall frost, which, naturally, is anyone’s guess in Colorado. Mid-October is usually safe. There’s a details at the end of this column.
IN THE LANDSCAPE
• Be sure to turn off your irrigation system while the ground remains wet. Too much trouble? Consider installing sensors to save money and conserve water. Your municipality may even have rebate programs for this equipment. More:
• Give your spring-flowering bulbs a light application of nitrogen before the foliage totally fades. If they have become crowded and need dividing, mark their spot now with a plant tag or a special rock. Dig them up in late August; let the bulbs dry for a day or two in a cool, shady spot. Re-plant the best and largest bulbs in a new spot. Wait until August to divide iris.
• Pinch the flower buds off of your mums until mid-July. You will be rewarded with fuller plants and more blooms. Use scissors to cut back an inch or two down from the unopened bud, and cut right above a set of leaves.
• Outdoor containers can dry out quickly despite all the rain, especially if they’re under an overhang that shields them from rain, but not sun. Water when the top inch of soil is dry. The general rule of thumb is to water the entire root ball until water comes out from the bottom of the container. Use your finger to measure dryness or try the inexpensive water meters sold in garden centers; they are very useful in indicating wet or dry soil. I use them all over my landscape, especially for new plantings.
• Cut off the flower stem, or “scape,” from fall-planted hardneck garlic varieties. This focuses the plant’s growth toward the bulb — plus you can eat the scapes in stir fries, pesto or hummus.
HEALING FROM HAIL
• Scientists define hail is a solid form of precipitation (no kidding). Last year I had seven hail events. This year it’s up to four, but it’s five if you count that it hailed two different times in one night. Ouch — and oh, what a mess!
• There’s nothing to for a hailed-on garden but get to work and clean up. Toss leaf litter and debris in the compost pile. Call in the tree professionals for large tree-limb damage.
• Gently cut back any damaged perennials. Follow up with a light fertilizer application and then water it in.
• Remember that there is time to replant annuals, perennials, vegetables, trees and shrubs.
• For smaller planting areas such as vegetables, annuals or perennials, it’s easy to rig up some inexpensive removable tunnels using rebar, conduit, clips and covers, and the how-to video is here:
INSECTS, DISEASES
• Usually the first indication of flea beetles is their damage, not the insect themselves. They eat tiny shot holes in leaves. Lettuce beds are a favorite food of some species, but there are different types and sizes of flea beetles that prefer certain plants or crops. The apple flea beetle is one you can’t miss. It measures under a quarter inch, is greenish blue and jumps or flies to get what it wants. What it wants is evening primrose, zauschneria, gaura, grapevine leaves and crab apple tree leaves. High numbers of these beetles can easily defoliate a plant, so act quickly. Organic controls include spinosad, horticultural oils and diatomaceous earth. You may need to make repeated applications, and be sure to read all label instructions before use.
• Leaf spot, fireblight, and fungal disorders are showing up in the landscape, most likely related to the heavy moisture and high humidity, but also the susceptibility of the plant. Get a correct diagnosis by taking photos and/or samples to your county’s Colorado State University Extension office or reputable garden center. More:
Betty Cahill: gardenpunchlist.blogspot.com; bettycahill@ymail.com
