I peeled the testa (hard outer seed coat) off of 24 Eureka Lemon seeds, laid them between four paper towels, two on the bottom and two towels on the top. Then covered it all with a hand towel. Whetted the entire surface and set the seed germinating pack in a 90F greenhouse. 18 of the 24 seeds germinated in just two and one half days (2-1/2 days). These seedlings will be used in a speed growing experiment. An attempt to get a seed grown Eureks to a mature flowering tree in 30 months (2-1/2 years) . More about the growth medium to be used later. The trial started the day the seed was laid on the paper towels. Everything will be recorded as the growth process proceeds. - Millet

I'm enjoying your recent experiments, Millet.

this sounds very interesting, keep us updated. It'd be nice to get things to mature faster.

Thanks for sharing this Millet. Fascinating experiments such as these are one of the many reasons I've enjoyed learning about this hobby and I hope to learn more from your results. Because of my mishap with the wind last week, I'm thinking about trying to germinate some more key limes and would like to do things differently (hopefully better) based on what I've learned here and from my previous mistakes. I would like to try peeling the testa on the seeds and germinating using your method and have a few questions.

First, is there a particular tool you like to use for peeling the outer coat (I was thinking about a sharp razor blade but am not sure if this is the tool for the job)? Also, are you determining germination by the emergence of the radical (through the thin brown coating that is still left I guess)?

I'm sure I'll have other questions but I believe you mentioned that you would be updating later with information about the growth medium and the environment you are using once they germinate so I will wait for your update.

BK

I peeled the seed using my fingernails, to split the pointed end of the seed, then peel down both sides. Peeling prevents the seed from benching. Benching (badly curled roots) restricts the flow of nutrients to the new seedling, and by doing so stunts the plant's future growth. This problem is common in cultivars such as sweet orange, and other citrus varieties. The new root grows around the seed between the cotyledons and the outer seed skin (testa) before emerging outside the skin. A useful but time consuming technique which prevents this problem is to peel the seed before germination. Peeled seed germinate in two days without bent and curled taproots. Peeling involves carefully removing the straw-colored hard, fibrous outer skin called the testa, leaving the delicate papery, brown skin around the cotyledons. The fine skin is very easy disturbed and the seed may fall apart if broken. Carefully place the successfully peeled seed on the paper as listed in the post above. - Millet

Potting Mix-#1 (Germinating Medium)
(Plant Production in Containers 11)

The best mixture for the early growth of seedlings is a combination of peat and coarse sand (preferably clean coarse river sand), or peat moss and perlite in equal parts by volume. Add the following nutrients to each cubic foot of the mixture.
152-grams 18-6-12* Osmocote Slow Release Fertilizer(No Substitutes)
17-grams STEM or Micromax micronutriens.
100-grams Dolomite* .

*Only 18-6-12 formulation of Osmocote (6-9 month formulation) is recommended since it has a slow initial release of nutrients, which coincides well with developing seedlings and the favorable nitrogen to phosphorus ratio. By incorporating a slow release nitrogen-phosphorus-potassium fertilizer such as Osmocote and micronutrients into the germinating medium, the seedling can begin absorbing nutrients very early, as soon as the first root (radical) is just a small stump of only a fraction of an inch long.

*Dolomite should be added ONLY if the irrigation
water supplies less than 25 ppm calcium.
Millet

Selected 18 of the best pre-germinated seeds and planted them into Root Maker Company's 4-inch 18 cell Root Maker Propagation containers, filled with the germination mix-1 listed above. Seedling remain in the Root Maker cell packs just long enough until the seedling's root system is able to hold onto all of the germinating medium when removed from the container. Then the seedling are transplanted into 3-gallon root maker containers (obeying the 4-inch rule) d. . - Millet

Hi Millet,

For your experiment, is there a particular variable you are testing or are you just using all of the methods you know of to ensure healthy, happy and fast growing citrus trees?

Oh, and I practiced the peeling method using an X-acto knife (thanks for the suggestion Bonnie!) on a seed I found in a minneola and it performed very well. I hope to try the method with new key lime seeds soon. Thanks again for the information.


Brad

Millet,

How is this experiment coming along? It has been about 7 months, and I was wondering how these seedlings are doing. Barbara

Hi Barbara, I have reduced the number of the seedling trees down to just one tree (the most vigorous). The tree is now 2-1/2 feet tall. The expected growth this coming Spring, Summer and Fall should be excellent. Lemons normally take 10 to 15 years from seed to maturity. I hope to get the tree to bloom in 7.5 to 8 years. My 2-1/2 year old "Clementine" hybrid, and my 2-1/2 year old Page Mandarin, both started from seed, are now blooming (30 months) for the first time. To be sure that the blooms set fruit, I sprayed them yesterday with a ten percent GA3 solution. - Millet (1,412-)

Thank you for that update, Millet. That is one vigorous lemon seedling! A question about your young Page and Clementine seedlings: about how tall are they and what is the trunk diameter? I know you have quite an advantage over me in terms of a greenhouse (and of course, there is also experience!). I don't remember reading anywhere the approximate size of a seedling mandarin that has reached maturity. Thanks, Barbara

Barbara, the seedling "Clementine" that is flowering for the first time this year is 33 inches tall with a 5/8" Diameter trunk (1-6/8 inch circumference). However, the size of the tree does not mean much when your trying to estimate when a seedling "Clementine" might begin to flower. I also have another seedling "Clementine" which is 52 inches tall with a 2-1/8 inch circumference trunk that has not yet flowered. Both were planted about the same time. I have put the word "Clementine" in quotes when referring to a seedling tree, because Clementine seed does not produce true from seed. So the seedling tree will be a hybrid of some type depending on what variety of citrus pollinated it. Therefore, the node count that needs to be reached (tree height) before a seedling "Clementine" matures, all depends on what type of citrus tree actually did the pollinating of the mother tree. I also have two seedling Page Mandarins. The tree that is blooming for the first time this year is 39 inches tall with a 2-2/8 inch circumference trunk (6/8" diameter). The other seedling Page is 47 inches tall with a 2-1/8 inch circumference trunk. Even thought the second Page Mandarin is 8 inches taller is has not yet flowered. - Millet (1,410-)

Millet!
How many flowers has the seedling "Clementine" that is flowering for the first time this year (33 inches tall)? What about its node count?
And the same questions about that blooming seedling of Page Mandarin (39 inches tall with a 2-2/8 inch circumference trunk).

The "Clementine" has 47 blooms. The Page Mandarin has 13 blooms. I sprayed all of the blooms on both trees with a 10 percent Gibberellic Acid solution to insure fruit set. Since a citrus leaf's life span is only 18-22 months on average, and the tree is 2-1/2 years old, not all of the leaves (nodes) are still attached to the tree. Therefore to get an accurate node count is not possible. - Millet (1,409-)

Thanks, Millet. I do understand the node count concept, and also that it is dependent upon the type of tree, and even the growing conditions. I was just wondering the relative size, and whether a seedling mandarin such as Page would be a prohibitive size for my house at maturity. I am sure yours is much more compact than one that I would be able to grow, since you have excellent year-round growing conditions, and I am dealing with winter conditions and inexperience.

I may have to work on my grafting and/or rooting skills to make the tree smaller if is gets out of hand! Thank you for measuring for me, Barbara