Twining Vine Garden Seed Store, Twining Vine Garden,

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Seed Information

Growing



> Germination testing

We endeavor to deliver you the best viable seed possible. In order to do this we conduct various tests in house to ensure your seed is live and will germinate. Remember seed, though dormant, is alive. Please store all seed in the refrigerator if you are unable to sow right away. Some seed such as tomatoes remain viable for 5-7 years when stored in a cool, dark and dry environment while others are intolerant of prolonged storage. Mind you, some seed (Magnolia, Panax, Paeonia) cannot dry out as this kills the embryo or causes prolonged complex dormancy which is hard to break or causes erratic germination. Life would be simple if we only had to pass or conduct one test in our lives, but what sort of challenge would that be? Specific instructions are included with all seed offered.

Candle test: some seed types (Fritillaria, Gladiolus, Lilium, Ulmus) are flat. Viable seed has a dark spot where the embryo resides. Duds are transparent. Those with dark spots are hand selected, duds are culled.

Cut test: a representative sample of 5-20 seeds of each lot is taken and with a sharp razor blade is cut to reveal the presence of an embryo inside. Duds are either empty or have a dry brown dead embryo inside. Embryos are plump white or pale green and fill their cavity. Duds are counted against the live, the percentage is calculated. Useful with Acer and others with a complex dormancy. Unfortunately the cut test destroys all live seed used in the test. Make me cry.

Finger test: the embryo is plump within the seed coat while duds are flat, soft, or deflated. Works well with dark/black seed such as Hosta and Agapanthus where candling is ineffective. Tedious, but this ensures a higher germination rate.

Float test: this runs on the theory that more dense viable seed sinks and the duds float. The floaters are skimmed off and discarded while the sinkers are collected and quickly dried (not using heat). This technique works well with freshly harvested or extracted seed, such as Ginkgo and tomatoes, but when the seed coat dries, there is enough buoyancy to cause the seed to float. Some species use floating as a dispersal mechanism to create new colonies. Seed with a high oil content float or barely float.

Germination test: a representative sample is taken from a seed lot and exposed to conditions to promote germination. This works well with small seed. The size sample depends on the size of the seed lot but usually 10, 20 to 100 seeds are germinated. The number of non sprouts or sprouts are counted (which ever are fewer). The germination rate is calculated. The germinated seed must be sown or the sprouts will die. I can't see hot-to-trot seedlings die and usually sow them in in pots and place them in an unheated greenhouse. No wonder I'm running out of room!