Q. I saved the seeds from last year’s tomatoes and pepper plants. When would it be a good time to start the seeds, so I can transplant them into the garden in May?
A. When germinating flower or vegetable seeds, I’d allow six to eight weeks between sowing the seed and planting in the open ground. Hence, I’d be sowing the seed in early March. However, if these were hybrid varieties, it’s not worth the effort and you’ll be disappointed. You only want to save and replant open-pollinated varieties. The seeds saved from hybrid flowers and vegetables varieties are unpredictable. The chances they are duplicates from last year’s varieties is not very good. It’s all about genetics, so I’d start with new plants. If not, the first thing to do is check to see if the seed is viable. Viable seed means it is capable of germinating. This is easily accomplished by pouring the seed into a glass of water or a larger receptacle. You discard the seed that floats on the surface and plant those that sink. The viable seed is dried out by spreading it over a paper towel and covering it with a second sheet. Next, sow the seed into a flat of pre-moistened potting soil, moist like a wrung-out sponge. With a pen or pencil, you make furrows in the soil, sowing the seeds in the rows and then cover the seeds. The flat is then covered with plastic to trap the moisture and heat. Once the seedlings start to emerge from the soil, remove the sheeting and place the flat in an area that gets morning sun. The seedlings are transferred to individual pots when they get two sets of true leaves. Some gardeners prefer to sow seed directly into individual pots and there is nothing wrong with that. But, I prefer the other method as it allows me to select and grow the most vigorous seedlings.
Note: May is an excellent time to plant vegetables, especially tomatoes and peppers. It’s not unusual for summer vegetables to struggle with cool and damp weather in March and April. So, there is a real advantage by waiting until May to plant.
Q. Last year, I planted cucumbers and was disappointed. They had a bitter, odd taste to them. A neighbor suggested that they were being pollinated by the squash plants growing near them? Will moving the squash to a different location solve this problem?
A. The problem will not be fixed by relocating the squash plants. Squash and cucumbers can’t cross pollinate as the genetic structure of the two plants are very different. Only members of the same species can interbreed. Squash will cross pollinate with other squashes, melons and pumpkins. This brings us to the next fallacy of this old-wives tale. If the two plants could cross breed, would it affect the current year’s fruits? The answer to this is also,” no.” When two plants cross pollinate, the results are unknown until the following year when you grow the saved, seed. Now this is a mute point if you plant new plants each year. Thus, cucumbers, squashes, melons and pumpkins can grow a side by side with no problems.
The bitterness in cucumbers is due to a naturally occurring compound called cucurbitin. All cucumber plants contain varying amounts of this compound that is triggered by environmental stress. Environmental stress comes from high temperatures, heavy soil that is too wet, dry, and/or drains poorly, low fertility, insects and foliage diseases. Many times it is a combination of many of these factors. However in the Bay Area, I believe that uneven or irregular watering contributes to the problem. This is particularly a problem when the growing season has below-normal temperatures in the spring, coupled with rapid changes in temperatures from mild to hot during the summer months. This is what we saw last year as April was beautiful, May was below normal and then we hit triple digits on June sixth. We then had triple digit heat spells in July, August and September. Bay Area gardeners tend to water with the same frequency regardless of the temperature. Yes, we water more when it’s hot but never less when the temperatures go below normal. The other factor is the soil preparation. Overall, it’s pretty minimal for our adobe, clay soil. Soil amendments must be added yearly in the spring to replenish what was lost last year. In addition, mulching is encouraged in vegetable gardens to even out the moisture and insulate the surface roots from the sun. Also, overly mature or improperly stored cucumbers may also develop a mild bitterness; however, it’s often not severe.
Note: The cucurbitin is often concentrated at the stem end of the vegetable and in the light green layer under the skin of the cucumber. You can limit the bitterness by peeling cucumbers from the blossom end toward the stem end and cutting off the last inch. It is best to rinse your peeling knife after each slice so as not to spread the bitter taste.