I had a conversation recently about saving seeds. The person mentioned some problems with seeds not coming true … specifically, tomato seeds.
(For those new to the gardening lingo “coming true” means plants grown from seed are exactly the species named on the seed packet.)
Chances of tomatoes not coming true from the seeds you saved are high unless you know that the tomato variety is an open-pollinated one.
Tomatoes are the most popular vegetable grown which is why they are a favourite with breeders who are constantly trying to develop an even better one.
And therein lies the problem. Many of the varieties of tomato seeds on the market nowadays are hybrids. They are the offspring of two different parent plants in the same species.
So if you saved seed from a hybrid, the resulting plants will not likely be the same as what you grew the year before. The new seedlings will be throwbacks to one or other of the parents in the original breeding.
For successful seed saving, you must stick to the open-pollinated varieties. But keep in mind there are what is called isolation guidelines for saving seeds from most vegetables and flowers. This involves having adequate spacing between different species varieties to guard against cross-pollination.
Luckily, tomatoes are one of the easiest vegetables to grow for saving seeds. With their perfect flowers … meaning they have both male and female sexual organs in the same flower … they are self-pollinating. Most often the flowers are pollinated before they even open which is a great plus.
Another bonus is bees are not particularly fond of flowers in the nightshade, or Solanaceae family to which tomatoes belong so there is even less likelihood for cross-pollination occurring. To be truthful, the smell of tomato plants does not attract me either.
So before saving your tomato seeds, double-check that the plant is an open-pollinated variety. (Hybrids are often labelled as “F1” in the seed catalogues.)
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Drat! Some of our tomatoes in the greenhouse have developed blossom end rot.
We should have replaced our old irrigation system that John had vigorously severed in a couple of places with the shovel but we opted to leave it for that notorious “next year”.
Blossom end rot is usually associated with tomatoes but other fruits such as squash and cucumbers can get it too.
The cause in all cases is a lack of calcium in the developing fruit so either there is not enough calcium in the soil or the plant is not able to absorb it.
Calcium is very necessary for the development of a strong cell structure. A deficiency of this mineral will result in weakened cellular walls that will begin to collapse as the fruit grows. This opens up the possibility for rot to set in, beginning at the blossom end…the starting point for developing fruits.
The only accurate way to determine if you have enough calcium in your soil is by having a sample analyzed by a lab. However, if you amended your vegetable bed with either ground calcitic limestone which contains calcium (Ca) or Dolomitic lime which contains both calcium and magnesium (Mg), then the soil is not at issue in this instance.
For plants to absorb calcium…or any other nutrients for that matter…from the soil, they must have adequate water. It is the only way nutrients can travel up into their vascular system.
The right amount of water delivered on a regular basis is important for the growth of your vegetables. It is especially important in a greenhouse situation since the plants are not exposed to rainfall. Uneven watering results in nutrient deficiencies for any developing fruit at a very critical time.
One further problem could be soil acidity, or pH. If the soil is too acidic (low pH) the calcium and other nutrients are “locked” in the soil and become unavailable to the plants. A pH of between 6.5 and 7.0 is ideal for most plants, allowing them to access the necessary nutrients for growth.
Knowing full well the perils to the tomato plants of irregular watering, it serves us right. We should have taken the extra time and dealt with the irrigation in the greenhouse. Never pays to cut corners.
Leslie Cox co-owns Growing Concern Cottage Garden in Black Creek. Her column appears every second Friday.