Soil temperatures might still be too cool
Like many of you, I bought my tomatoes and peppers at one of the Master Gardener's spring market sale. It was so cold and rainy that I wasn't overly enthusiastic to get out and work in the garden so I grouped my plants together, sat them next to the garden shed for a little warmth and protection and decided to let them be.
Then, ignoring what experience has taught me, I decided to put them in the ground. And I paid a price for my impatience.
Planting too early in cooler temperatures can cause stunted growth, wilting, surface pitting, foliage necrosis and increased susceptibility to disease. Low soil temperatures can stunt plant growth and prevent root development. Most summer vegetables like soil temperatures of between 55 and 65 degrees.
Because my plants had just come from a greenhouse, where they were pampered with lots of light, water and warmth, they really needed to be hardened off before planting. Hardening off means to keep your seedlings in protected area, such as a porch or garage, and gradually acclimate them to their new environment, placing them outdoors in a shady spot for a couple of hours and slowly increasing the time. Plants that aren't properly hardened off are much more susceptible to sun and windburn as well as breakage.
We also recommend planting your seedlings into larger containers as soon as you bring them home.
So what happened when I didn't follow the prudent planting process? Well, one of my tomatoes snapped in half and I have a couple of peppers that look very much like the sad little tree in “A Charlie Brown Christmas.” I'll be starting over with some new seedlings and a bit more patience.
Tips for planting
- Plant your tomatoes deep (up to leaves you didn't pinch off)
- Amend soil with a high-quality compost (if needed)
- If planting in containers or raised beds, add slow release, organic fertilizer and compost
- Add tomato cages when you plant, if you wait until they need the support you can damage the roots
- And remember, peppers and tomatoes need 6 to 8 hours of sun. They also like well-draining soil and a pH of 6.5-7.0.
- Mulch around plants to help retain moisture and cut down on weeds.
- To avoid fungal issues such as fusarium and verticillium wilt, don't plant in the same area for 3 years, if possible.
- To avoid blossom end rot, make sure to provide consistent and deep watering.
- One of the most common tomato ailments is tobacco mosaic virus so don't smoke in or near your garden.
- Look for plants that are labeled disease resistant.
- The rains are tapering off, so make sure to keep young plants well watered. Peppers like to be kept evenly moist, but once tomatoes and peppers start fruiting you can significantly cut back on their water.
by UC Master Gardener Rebecca Jepsen
Photo: Rebecca Jepsen
This article first appeared in the April 30 issue of the San Jose Mercury News.