Any experience in using sea kelp additives on orchids?
 

Has anyone here tried to use kelp extract on orchids? It's classified as a "plant stimulant" or "plant growth regulator". It's not the same as regular fertilizers. Through a project my company worked on in Alaska to map kelp resources for harvesting, I know it is used commercially by apple and other fruit growers to, for example, help all the fruit ripen at the same time to lower the costs of harvesting. In other plants it supposedly maximizes bloom size and aids root development. I still have some concentrated product from that project which used to be marketed as "Garden GROG", and would like to try it on some of my orchids. But thought I'd throw this out first for advice. (The marketed kelp additive is not just ground up kelp with lots of deadly salt in it - it took over a year of "fermentation" before it was packaged for sale)....

I use Seasol, which is a commercial seaweed extract sold here in Australia, on my orchids in addition to normal fertilisers. For heavy to moderate feeders I use it at the recommended strength mentioned on the label. For light feeders I use 1/2-1/4 the recommended concentration.

There is a pelletised fertiliser that has recently come on the Australian market developed for use on Cyms that contains seaweed extract as an ingredient. While this fertiliser doesn't cause problems on its own I have heard that some Cym growers have reported virus-like symptoms on their plants after using this fertiliser in combination with liquid seaweed extract. I take it from this that seaweed extract might cause problems for orchids if you use more than what the manufacturer recommends.

I use Maxicrop Liquid Seaweed in the spring when I see new roots starting. I wouldn't use it this time of year because you don't want to stimulate growth when the days are short and the plants should be using their energy to bloom. Liquid Seaweed is the only additive I've ever used that had a result almost immediately. All my plants started growing larger and more abundant roots within a few weeks of starting it. I haven't noticed a difference in the number or size of flowers but my plants all developed large healthy root systems. It doesn't replace fertilizer. You still need to fertilize like normal.

ive heard of people having good results with that

Good results with Maxicrop Liquid Seaweed, used with fertilizer at regular strength, robust roots systems.

Its definitely a PGR, (kelp contains huge levels of cytokinins) and does pretty much what everyone has said they have seen, root development.

I too use light dose of maxicrop seaweed every now and then along with regular feed, chids seem to love it.

Thanks so much to you all - looks like we have a pretty strong consensus on the benefits of kelp! I'll definitely give it a try and will report on what happens for my plants.

Jan S.

I've used it successfully with all orchids on a regular basis, including Bulbos. The most successful grower in our little Society also uses SuperThrive along with fertilizer and kelp extract. His plants are spectacular. Although I tried SuperThrive as well for a couple of years, it didn't seem to make any difference, but the seaweed extract really did make a difference. I used 1/4 recommended strength each for seaweed and fertilizer every time I water. Larger hanging plants, get summer-watered 2 x per day, winter water once every 2 days. The very small mounted hanging plants are misted at least every day in winter because the heaters tend to dry them out rather quickly and I don't use overhead misters in winter.

Sine it's organic I don't think you can burn the roots either. Or mess up flower spikes