Repotting is a traumatic experience and can cause an orchid to undergo transplant shock. Transplant shock may result in an orchid taking a long time to start growing or to produce flowers. I liken repotting to someone undergoing major surgery. It takes time to recuperate from the trauma of surgery, likewise, it can take time for an orchid to recover from the trauma of repotting. Liquid seaweed extracts/concentrates contain growth hormones, nutrients and other compounds that can gently stimulate a repotted orchid to grow and recover from transplant shock.
The best time to repot your plant is when it is showing signs of active growth. Generally, this will be during the spring and summer months or when an orchid is growing new roots. Repotting during the growing season will allow the orchid to settle in and produce a good root mass.
Take extreme care not to damage the roots when repotting, particularly the tender growing tips.
The orchid I have chosen for this demonstration is a latouria dendrobium. After 14 months from repotting, it has not done well and is deteriorating. I am hoping that changing the potting medium and the regular application of a seaweed concentrate will help to get it growing again.
The goodies I need for this are:
The first step is to soak the orchid for about 30 minutes in the seaweed concentrate mixed at 1 part seaweed to 250 parts water. This equates to 4 ml seaweed concentrate to 1 litre of water. Soaking will soften up the potting mix and roots and this will help reduce damage to the roots when removing the old potting mix. Obviously, the roots will absorb some of the growth-promoting compounds during the soak.
After soaking remove all the potting mix and any dead or damaged roots. If required, break the plant up into smaller pieces and choose a pot size that will allow for 2 to 3 years of growth.
This orchid has finer roots therefore I am going to use a potting mix based on Kiwi bark size number 2, which is from 3 to 8 mm in diameter. The reason for this is the smaller size of the potting mix will hold moisture in reserve for longer. Thin orchid roots do not hold as much moisture as the thicker roots. The roots will be able to absorb some of the reserve moisture held in the potting mix.
Place some limestone chips at the bottom of the pot. I have noticed that when I use limestone chips, my orchids seem to be healthier than those that do not have limestone chips.
Next, place the roots into the pot and pour in the potting mix. Place enough mix to ensure that the roots are covered so that the bottom of the rhizome is just sitting on top of the potting mix.
Drench the potting mix with a solution of seaweed concentrate and a reputable orchid fertiliser. Continue using this mixture once a week for 4 to 6 weeks after repotting. As mentioned earlier this will help the orchid overcome transplant shock and hopefully start the growth process. After this 6 week period, revert to using a seaweed concentrate once a month and fertilise as you normally would. Remember you should only repot your orchids when they are actively growing which is during Spring and Summer.
Another application for seaweed is to encourage root development on monopodial type orchids (leggy orchids). The regular application of a seaweed concentrate should result in the development of roots and break bud dormancy resulting in new growths developing.
To encourage root growth, apply Ocean Organics Soil Concentrate for 4 to 6 weeks as a foliar spray and pot drench, then revert to applying it once a month.
Use at a dilution rate of 1:250 (4ml seaweed concentrate to 1 litre water).
Applying seaweed concentrates weekly for an extended period of time may result in your plants producing deformed flowers. This is caused by the action of the growth hormones on the orchid. This is why I don't recommend more than 6 weeks of a weekly application. If this occurs stop applying seaweed for 2 or 3 months and then revert to applying it once a month. Fortunately, this does not cause permanent damage and given time your orchid will revert to producing normal flowers.
All plants whether grown in a pot or in the ground will benefit from transplant shock treatment described above.
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