Hand Pollinating Delphiniums

Hand pollination is easy and very rewarding.

There is something magical about producing your own hand crossed seed, the characteristics for which have been selected using plants that appeal to your tastes. Below are a few photographs which may help those of you wanting to give it a go.

The prime consideration of cross pollination is to get the ripe pollen from the desired male parent onto the ripe stigma of the female parent, preferably without contamination from other pollen sources.

De-anthering the female parent: just before the flower buds have opened (when a small hole can be seen at the opening end of the bud) is a good time to de-anther. The floret should be carefully opened by hand and the "bee" petals removed. Next, take the unripe anthers between thumb and forefinger and, using a gentle squeezing and pulling motion, remove the anthers. This will leave a rather ratty looking middle to the floret. The second picture below shows florets with anthers removed.

Several days after the anthers have been removed the stigmas should be protruding (the time will vary with variety) and ready to receive pollen (see the second photo). The best way to test this is to apply pollen and check to see if it sticks to the stigma (you will need good eyes or a magnifying glass) I usually pollinate the same flower every other day, 2 or 3 times just to make sure. You will quickly get your timing right by observing the pollinated florets over the next few days and seeing which begin to swell. If you are doing this for the first time I suggest you try pollinating different florets at different stages to see which works best.

We usually use the pollen fron the male parent after several anthers are ripe. Ripeness is indicated by the anthers turning white with pollen which will rub off onto your finger quite easily. Rather than use a brush, which has to be cleaned with each change of variety, to transfer pollen we simply remove the flower containing the ripe pollen from the plant, carefully take off the bee petals, and simply apply the exposed pollen to the stigma of the receiving plant's florets. A point to note about pollen is that the younger the pollen on the ripening anthers is, the less likelyhood there is that it has been contaminated by foreign pollen transfered by bees or other insects and the more likely it is to live long enough to grow.

That's all there is to it. Simply harvest the seed when the pod is ripe. That is when, or just before it is splitting, and before the seeds start to spill out.

Have a look below!!
(click any image to see a larger version)

hp1delphinium darkbluesmHere is a section of a single flower spike from a seedling B9709) and clearly shows the central white "bee" which must be removed, along with the unripe anthers
(male parts), to obtain a female parent. This operation is best done just as the flower begins to open before pollen has begun to ripen).
hp2deanthered bluesmFlorets with the bees and anthers removed about 5 days previously. The stigmas and darker overies can be seen inside the white ring of de- anthered stamens. Note the extended, upward pointing stigmas which, at the top of the photo, will have been pollinated in the last day or two.
hp3seed pod closeup smFlorets with ovaries swelling with seed. The seed should be harvested when the pod begins to turn brown and bursts open. Note how well the petals of this variety are holding on the plant, long after seed set.
hp4Deanther TooYoung2 2005smThs stigma on this deanthered floret is not ripe - too young to be pollinated.
hp5Deanther Ready2 2005smThis stigma is standing up straight and ready to be pollinated. Look closely at the end of the stigma to see it open, ready and waiting.
hp6Deanther TooOld2 2005smThese stigmas have already been pollinated - you can see pollen sticking to the end and the seed pods beginning to swell.
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Dowdeswell's Delphiniums - Wanganui, New Zealand