June Planting Tips

Sunshine. Southern Oregon has a lion's share of that summertime commodity. But if you're just starting to plant a garden in June, the sun can be foe as well as friend. Here are a few hints to make late-spring planting successful.

"All veggies need full sun," says Mike Soderlund, manager at south Medford Grange Co-op. "They are a short-term crop, and they thrive in the sunshine."

Full sun means at least six hours of direct sun. The trouble starts when small, tender, greenhouse-raised plants meet the valley's big, bad June (and July and August) sunshine. The cell-pack plants wither from the heat. Their small root systems can't move enough water through their stems to keep leaves moist. These plants can wilt and die in an afternoon. Growing from seeds is a problem for the same, sunny reason.

"Once the temperature hits 86, you can't sprout from seeds and get a quality crop," he says. "We've all tried, and we've all gotten the same success, which is minimal."

The solution he suggests: Bigger is better.

"Start with gallon-sized plants," Soderlund says. "Something that has its roots established. It's instant gratification."

Another reason not to use cell pack-sized plants in June plantings is time. If you have a plant that requires 80 to 120 days to maturity, planting in June means you'd need a long, warm fall to get the maximum harvest, Soderlund says. Growing time is made even shorter because of the heat. When temperatures hit 86 degrees, plants move into a dormant state. Leaf pores close up to prevent water loss, and growth is halted. They survive the high temperature, but you are left with plants that don't thrive well enough to provide a full harvest.

So for any plant put in the ground during June, choose a variety with a shorter growing season and a high heat tolerance. Cool-season spinach won't make it, but Jackson County master gardeners suggest planting Malabar spinach through mid-June, or New Zealand spinach all month. Amaranth leaves can be used as a spinach substitute.

For the best harvest of basil, squash and cucumbers, get those transplants into the ground before mid-June.

Toni DeVenney, nursery sales associate at Ray's Garden Center in Ashland, suggests optimizing soil health with compost and fertilizers. Vegetables and ornamentals need differently balanced nutrients to thrive, so check the plant label for instructions, says DeVenney. Heavily blooming ornamentals and fruiting plants need more phosphorus than leafy-green nitrogen lovers. Vegetables need fertilizing once a month, she says.

Sunshine makes deep watering a necessity, says Soderlund. Even young shrubs and trees can die without deep watering, he says. "It's very good preventive medicine."

June is a good time to start seeds for your fall garden, if you can protect them from the weather extremes.

"You can't leave them in the heat of the noonday sun," says Soderlund.

Keep moving the transplant up to bigger pots as it grows in order to develop a healthy root system.

The final word for gardeners? Keep your eye out for weather variations.

"The weather has been really crazy this year," DeVenney says.

Even with hot days, freezing temperatures are possible at night, especially in higher elevations. Plants in shady spots or with north exposures might be susceptible to damage. Use large rocks or water-walls to help keep the temperatures around plants higher and prevent damage.

Gardening in June — for lion tamers only.

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