Is Summer over YET?
I honestly feel this summer has dragged on much too long. With constant heatwaves and record temperatures across the country, both us (and our plants) are ready for a break.
The good news is that as soon as fall arrives we can start looking forward to different plants setting spikes and buds in response to the cooler weather. So what should you be doing to anticipate that?
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By now growths from the spring and summer have finished maturing and need very little fertilizer to keep them happy. As we have mentioned before, you should be using low nitrogen fertilizers or even gradually tapering your feed program to the cooler months. Plants that go dormant do not need any more fertilizer until spring. If you are hoping for spikes on your Phalaenopsis and Cymbidiums, you can switch to Grow-more 6-30-30 Bloom Booster, or Jack's 10-30-20 Bloom Booster since the Nitrogen is much lower and the Phosphorus and Potassium will help encourage stronger stems and brighter coloring. Keep in mind, Bloom Booster doesn't mean is makes the plant flower, it just helps the process along.
So what makes those spikes emerge? Orchids bloom in response to environmental triggers. That could be day to night temperature changes, length of daylight vs darkness, increase or decrease of watering, or any combination of these. A good example would be the famous Cattleya mossiae that were used in cut flower corsages at Easter and Mother's Day. If you needed 6,000 blooms for Easter but that holiday changes each year, how do you plan for it? Cattleya mossiae blooms in response to A) length of day. Adding strings of incandescent bulbs that became forcing lights tricked the plants in thinking spring was closer than they think. And B) overall temperatures. Back in the day under the bench radiant heating allowed for an increase in ambient temperature that told the plants, you guessed it, that spring was coming. All of these changes encouraged the plants to set buds on a specific schedule and allow for harvesting on time.
A similar process is the reason you can get Phalaenopsis in
bloom from the stores year round. As recent as twenty or so years ago, Phalaenopsis season was very much a springtime event. The spikes started in the mid fall, when temperatures dropped 15-20 degrees and would mature to buds by Valentine's Day with blooms not long after. Mother's Day was the expected end of the Phalaenopsis season. Nowadays, large nurseries around the country utilize cooling technology to encourage plants to produce spikes year round. So you can purchase a freshly bloomed Phalaenopsis for the Fourth of July if you so wish.
For the average home grower, fall temperatures are still the best way to encourage new spikes. After a summer of growing with good light, your Phalaenopsis and Cymbidiums will need the addition of a temperature drop to trigger the bloom stage. The former would like temperatures to 58°-60° degrees for at least a few weeks. This can mean a covered back porch or deck. Perhaps an unused bedroom where the heating vents are closed. A covered garage near a window (they still need light) would also work. After 2-3 weeks, you should start seeing the first signs of a spike nubbin. Mature plants spike faster than seedlings.
Cymbidiums on the other hand will go even colder and for longer. Since they require so much light, many growers will have them outside for the summer months, or in a greenhouse. The best option is to allow them to reach the mid to upper 40's for several weeks. As long as they don't freeze, they are fine. Spikes can take a while but usually are visible by the holidays.
Once the spikes emerge, avoid drastic temperature swings as this can cause the stems to stall or the buds to blast (wither and drop prematurely). Good airflow, consistent watering and no changes in light direction. The spikes will follow the light source, so if you move or rotate the plants, those spikes get confused.
Ideally, all repotting for winter blooming plants should be done before now with a good root system established. Anything lacking strong roots should not be encouraged to flower, as this will stress the plant. It is better to wait another year to see blooms versus weakening the plant or losing it entirely. A good policy is that spikes or buds on weak or non-established plants should be removed as soon as possible.
Now, you just need to stock up on plant stakes and clips to be ready.
Happy Growing!
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