Sowing Rhododendron Seeds

for the optically motivated

Occasionally Dr Dave Goheen, of the "ABC's of Rhododendron" fame,
puts on a clinic in how to raise rhododendrons from seeds.

It is a lot easier when you watch an expert do it

Here's How

First, you need seeds. Not just any seeds, but rhododendron or azalea seeds.

Secondly, you need a commitment of time and attention.

Very small rhododendron seedlings die easily if you don't give them the right kind of care. If you do give it, they will need very little attention for the first year. After that, They will require a year or two of TLC before you will be the proud parent of your own genetically unique rhododendron.

With such an investment in time and effort, maximize your chances of coming up with a show winning plant by making a carefull hybridization.

Almost all members of the genus rhododendron have both male and female parts in one flower. The stamens (male) are the thin pieces with the brown on the end in the picture at right, while the brown ends are called anthers. The stigma is the red-tipped end of the thicker filament and represents where the female part of the plant first recieves the pollen. The little droopy white stuff at the ends of the anthers is the pollen.

Here you see a flower of the dwarf species R. mekongense. The stamens are around the outside, and the stigma (here green) connects via the style to the ovary at the base center of the flower

Find an almost-open bud on the mother, or "seed parent" plant. Carefully peel away all of the flower petals and the pollen-bearing stamens, being careful not to touch the stigma. Remove any buds around the site so that no bees will be atrtracted to this flower later.

Find anthe stamens. Pollen can be stored for up to a year in gelatin capsules open flower on a pollen donor plant and remove the freezer if needed. Take the pollen from the male parent plant and apply it to the stigma of the seed parent. If the stigma is not sticky (receptive), feel free to reapply the pollen several times a few days apart.

Deflowering the recipient bud before making the cross serves more than just as a symbolic gesture of the hybridizer asserting his authority over his plant. The common vector for pollinization is the bee. If you want to be sure of your cross, make sure that the bee is not attracted to the site of your cross. You could enclose your cross in a bag of nylon stocking if you want ( sort of a modern chastity belt for after-the-fact).

You will probably forget the parentage of your cross before the fall harvesting season starts. You might not even remember which plant and where on the plant you left your crosses.

SO LABELLING AND MARKING IS VERY IMPORTANT.

Make real good record and tie a big flag to the spot of the cross.

	Here's a closeup of the previous picture. You can see some very swollen deciduous azalea seedpods in the picture, along with several pods that were never fertilized and haven't produced any seed. These are the small podlings directly in the center of the picture.
Pod harvesting takes place in the fall, around October-November. Pick the pods when they turn brown and dead, preferably before they dry out. Bring them indoors and let them dry out. Usually the pods will open by themselves. If not, crack them open.

Separate out the seeds from the pod fragments onto a sheet of white paper. Save the seeds in a glassine envelope of folded paper. Don't use a plastic bag, because then the seeds will mold. Duff put into your seed pots will also mold. Seeds can be planted anytime that you're ready.

Now we get to the actual seed starting procedure.

Collect some small containers for the starting mix, and a larger container to put the small comtainers into. Two inch pots are excellent, and many fast food and greengrocer establishments have clear plastic containers to use for the outer container. As potting mix, straight peatmoss works the best. Use a no-damp-off spaghnum if you can get it, otherwise use a regular sphagnum moss and the fungicide captan, as described later.

Wet the spaghnum thoroughly, then squeeze moderately dry and put it in the 2 inch pot. put some of the seeds on a sheet of paper and sprinkly it widely across the surface of the pot. Too thick, and you'll have too much work transplanting seedlings later. You don't need to cover or bury the seeds

If you used no-damp-off spaghnum, your seeds are ready now. Otherwise cover the surface of the seedpot with a light dusting of captan fungicide. This will keep damp-off fungus and other fungal attacks from ruining your project. Then label your seedpots with some indelible marking so that you will know the parentage of the seedlings later. Almost all seedlings look alike!

Seeds do not require light until after they germinate in about 3 weeks

Here is an enclosed cookie box with seed pots inside. It hasn't been opened in the 3 months since planting.

Always keep the box out of direct sunlight. Fifteen minutes of sunlight is enough to parboil the seedlings.

These seeds in the box above have developed a second set of true leaves after the original colyledon seed leaves. The seeds (in the box above) were planted a little too thickly and will be hard to transplant.

Use a seed starter soil mix and more 2 or 3 inch pots. Use a knitting needle or something similar to tease the seedlings apart. Plant several in each new pot. Dust with captan fungicide. Place in a box and cover with glass or clear plastic. I put mine in an enclosure where they get automatic water misting for the first month. Premature drying before the roots get established is the greatest danger to their survival.

Here is the growing-out stage of the seedlings. Several to a pot, with never a chance to fully dry out or sunburn.

When these get big enough, they will undergo one or two more up-sizing transplants before they are ready to go out into the garden