Growing Bromeliads from Seed

By Odean Head

Most of my experience has been with neoregelias but the procedure should be similar for most of the genera in the Bromelioideae sub-family. Growing seeds from the Tillandsioideae sub-family (Tillandsias, Vrieseas, Guzmanias, etc.) is quite different and its procedure is not included here. We must have some mature seeds before we can plant them. If our pollination was successful, we should have some mature seeds in three to six months. Remember, many bromeliads do not self pollinate and therefore depend on birds, insects or us to do the job before any seeds will develop. The seeds will form in a berry-like ovary located beneath the pollinated flower. The ovary will begin to swell in a month or two and will usually change to darker colors as the seeds mature. The best way to tell when they are ready to be harvested is to pull lightly on the seed pod. If it releases easily, the seeds should be ripe.

To harvest the seeds just squeeze the pod between your fingers and the seeds will squirt out the bottom end. The seeds will be in a sticky jelly substance that will make them harder to separate because some of them will try to stick together. Most people recommend that you wash and dry the seeds before planting. Squeeze the seeds into a small closeable container, add an inch or two of water and a drop of detergent, let them soak for an hour or two and shake it periodically. Strain the seeds and remove any pulp that came from the seed pod. Wash the seeds again with clean water and spread them on a paper towel to dry. When thoroughly dried spread them evenly on another paper towel cut to fit the container you are going to plant them in. If you prefer to plant them later just store in a dry, cool place and they should remain viable for several months. If you have more than you can use, Harvey Beltz would love to have them for the BSI seed bank. Just be sure to label them properly so that he knows what he is distributing.

Usually I am either too lazy or in too much of a hurry to use the seed drying procedure. I just squeeze the seeds directly on to a paper towel for planting. I use a plant label for the mass spread and a toothpick to separate seeds that are stuck together and to remove any pulp squeezed from the pod. This has been successful for me and expedites the overall procedure.

The planting medium should have fine texture. I use a mixture of one-half peat moss and one-half vermiculite. Since this mixture is hard to wet I pre-soak it before using. A good preventative measure is to add some fungicide to the water when you pre-soak the medium. Since the germinating and growing area for the seedlings will remain very humid for a long time it is susceptible to growing fungus. Starting with a sterile medium will help prevent this. Fill the pot (I use a 5" or 6" pot) about half full and firm it so that the top is smooth. Place the piece of paper towel containing the seeds on top of the mix and smooth it out. Do not cover the seeds. Cut a piece of plastic or saran-wrap and fit it on top of the plastic pot securing it with a rubber band or strip of panty hose. I prefer the panty hose because it does not deteriorate like the rubber bands do.

Put the pot in a warm, reasonably good light (not in full sun) and wait for the magic to begin. In about a week to ten days you should see the seeds begin to germinate. Very little care is needed in the next two or three months. The covered top will hold sufficient moisture in the pot for some time which will be evident by the moisture clinging to it. The seedlings like continuous humidity so if the mix appears to be drying out, don't wait too long to re-wet it. Watering at this stage should be done from the bottom by setting the pot in about an inch of water. Top watering when the plants are small could wash up the tiny roots and cause considerable damage. When the plants get about one inch tall I will remove the plastic and begin top watering using a weak fertilizer solution (one-fourth strength). The plants are still fragile so I use a suction cup (used in cooking for basting) and apply the solution very carefully around the tiny plants. I do this every two or three days.

When the plants become crowded in the pot I will move them to a community tray to keep their roots from becoming too entangled. Plant them about one inch apart which will provide space for additional root development while staying close enough to aid in retaining desirable humidity. I will continue to water with the baster until the root systems get well established and the plants appear to be strong enough to support overhead watering. I will also continue to water with the weak fertilizer solution often enough to keep the mix from completely drying out. If the seedlings are not already growing in good light (filtered sun), they should be moved there when placed in the community trays. This will reduce the legginess which would result from the continuous fertilizing.

I let the seedlings grow a long time in this community tray. In fact some of them may never leave the tray. As the plants grow and start to crowd each other they began to differ in appearance. This is where the culling procedure should start. Select only those that are beginning to show good potential and pot them into individual pots. You may go back to the tray several times as the plants grow for more selections or you may decide to throw the rest away. Look closely before you throw them away because sometimes the runts become the best cultivars. You may grow most of the ones you selected to maturity before making the final selection(s). Grow them under ideal conditions so that you can be sure of their potential. This will make it easier to cull. Try growing some.


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