These subjects, I believe, really cause anxiety for new hydroculture people. Why? When I quit soil-growing and started hydroponics, I had no clue about determinate and indeterminate plants and I was mostly ignorant about hybridization, pollination, and cloning. I threw a few tomato seeds into some potting mix, watered it, dug a hole in the ground, threw it in there, and waited for tomato plants to pop up.
I bought packets of tomato seeds from WalletSweep Mart because they had pretty pictures of big, ripe, and juicy tomatoes. I hardly ever read the back. I never cloned plants and I never saved seeds. Heck, I live in the South! You can throw anything into the ground and it will grow. The South is one giant greenhouse during the growing season. We've got rain, sun, bees, insects, and birds. That's how plants eat, drink, and “make whoopee,” right?
Sometimes I got really tall and crazy vining tomato plants that outgrew the wire cages. They grew and grew and produced tomatoes until the plants were frozen in winter. Other times, I got short bushy tomato plants that “busted out” with a gazillion tomatoes all at once, and then the dang things would wilt and keel over! I was too cheap and lazy to study the problem or ask anyone about them. As long as I could buy new packets of seeds, I was good!
Here is the difference between determinate and indeterminate plants: determinate plants are usually short and bushy. A “terminal bud” will bloom at the end-point on the stems. The plants will set all their fruit at once and then die off.
Indeterminate plants will usually be taller, and vine or branch significantly more. You usually have to prune out the “suckers,” or lower branches. They will grow blossoms and fruit until the cold weather kills them. If you are good at it, and you have a heated greenhouse, you can keep an indeterminate plant going through a couple of seasons.
An “heirloom” plant is one that is not a “cross-breed,” or cross-pollinated, and is not a “hybrid,” or close pollinated. It is bred from parent plants of the same genetic strain. An heirloom plant can be determinate or indeterminate, but most are determinate. Some enthusiasts say that the line has to be at least fifty years old to qualify as an “heirloom.” Heirloom plants are always open pollinated. If a plant is self-fertilized, or close pollinated, and the offspring retains the genetic traits of the parent plants like heirloom plants, then it is “true-bred.”
A hybrid plant is simply one that was carefully cross-bred (cross-pollinated) from two different varieties by the grower for specific traits, such as heat/cold hardiness, disease resistance, color, fleshiness, sweetness, shipping hardiness, and other needs. Most hybrids are commercial, but some gardeners will grow their own. A hybrid can be determinate or indeterminate. Hybrid plants, by their their nature, are close pollinated. The first offspring of a hybrid is usually called “F1.” There is a lot of work for the grower, so seeds are generally more expensive.
So what is open pollination and closed pollination? There is a lot of science, confusion, big words, and general discussion about pollination, so here goes:
Open pollination is what nature has done to propagate plants for eons. Insects, bees, birds, animals, rain, and wind can pick up and move pollen from one plant to another. Pollen is the fine powder “male” part of the donating plant, and the pistil, or the “female” part of the receiving plant has several parts, including the stigma. The stigma accepts the pollen and begins the process of fertilizing the ovary. Many steps later, seeds and fruit will begin to form. They have “made whoopee” and are now the proud parents of a plant that will mostly look like them. Even with open pollination, most plants will “true breed” and mostly be alike, with few variances.
Closed pollination can be natural, or artificial. Some plants are naturally close pollinated, or self-fertilized. I have a personal example of a plant that is a determinate, and could be both open and close pollinated! I attempted to grow a Crimson Sweet watermelon (on a dare from my son) in a HydroSock jug. I got seven feet of vine but no fruit. Outside of grow rooms and greenhouses, my watermelon would have been pollinated by bees or other insects by open pollination, but here is the part which makes this one close pollinated: a watermelon creates male and female flowers on the same plant! The male flower must bloom first and then the pollen has to get from the male to the female flower to create fruit. If it gets done by bees, wind, rain, etc., then it is natural, and open pollination. If, however, you have no natural pollinators, then you have to do it yourself! That is artificial, or hand-pollination. It is also close pollination.
I was growing a single watermelon plant indoors -no natural pollinators in my house- so I needed to use a soft brush to collect the pollen and dapple it into the female flower. Except that I didn't get that far. I damaged the main stem, and the plant took forever to grow the male flower, which never did mature. I never did see a female flower. And yes, the male and female flowers look different! Most watermelon varieties, with field separation of a mile or so, will “true breed” with open pollination. Watch the watermelon challenge video here.
Here's another personal example of a close pollinated -and indeterminate- plant, the Jet Star hybrid tomato. I grew the Jet Star several years and had great success in my little HydroSock jugs. They grew nearly ten feet tall and were prodigious producers of large, low-acid and super-sweet tomatoes. They bloomed over and over and kept growing tomatoes as fast as I could eat them and give them away.
With just five jugs, I estimate that I grew hundreds of 4-inch and larger tomatoes. I had no bees, and few insects in my greenhouse, so how did they get pollinated? I shook them! I pulled on the strings I used to support the plants and shook the pollen from one part of the plant to another. I also sprayed water over the plants from time-to-time to keep them moist. That also helped to pollinate the tomatoes. Watch the video (and my stupid singing!) here.
While you can save seeds from all heirloom and some hybrid plants, the offspring of hybrid plants, if grown from seed, may vary widely, with possible unwanted and unusual traits. It's better to clone a hybrid tomato. I took cuttings from my hybrids and put them into a cloning solution, and presto! - more tomatoes exactly like the donor plant! While I'm not an expert at cloning, most plants can be cloned, and it's not as hard as you might think. You can buy commercial cloning solutions, or you can make your own (the web is chock-full of recipes and tips.)
Here is a trait where heirlooms beat the pants off hybrids. You can save heirloom seeds for years ahead but coming up with future copies of your hybrid tomatoes is mostly short-term and unpredictable. You'll likely buy more seeds and the next crop will not be exactly like the last one. The later crops will usually be hardier, and more disease-resistant, though. That is a definite advantage for hybrids.
I am now attempting to grow determinate tomatoes called Rio Grande -a relatively new Roma-variety- in a new modification of the HydroSock jug. They will grow short and bushy, and set fruit all at once. They are normally open pollinated, but I will have to hand-pollinate them since they will be in a greenhouse. They are still classified as open pollinated but will be artifically pollinated.
Whew! I could go on and on, but this is really all that most people need to know. Now you can buy seeds with confidence and actually have a clue, unlike cheap and lazy Plain 2 Grow Jim!