Repotting houseplants to hydroponics forces the plant to change it's soil roots to water (hydroponic) roots. Most plants do this without incident - but for some - it can be stressful.
Any plant can be grown hydroponically, but some plants have difficulties converting from soil to hydroponics.
Some plants struggle during the transition because they insist on developing new roots rather than adapting their existing roots.
Growing new roots takes time and the plant often goes into stress. Creating an ideal environment for new root growth is the key to success.
The two most important factors for growing new roots are 1) warm temperatures at the root zone and 2) increased the humidity at the leaves.
Being the tropical creatures they are, houseplants need temperatures of at least 68 degrees at the root zone for roots to grow. If temperatures drop below 68 degrees root growth stops. (That's why transplanting during the summer months is better than in winter.)
When roots become inactive, bad things happen and disease or decay sets in quickly.
Warm temperatures at the root zone keeps roots active. The best way to insure warm temperatures at the roots is growing on a Heat Mat. Heat Mats warm the root zone gently and evenly without raising the air temperature at the leaves.
Grower Tip: Never place new transplants on radiators or near heat vents from the furnace to keep the root zone warm. Radiators get too hot and air from the furnace is extremely dry which effects other parts of the plant. Heat Mats are the only way to raise the temperature at the roots.
As plants grow, they release moisture into the air. This is called transpiration. Transpiration accounts for 90% of the water used by the plant! Only 10% is used for growing!
Slowing the rate of transpiration reduces the pressure on new roots to perform because less moisture is needed at the leaves.
The rate of transpiration, or how much moisture is released at the leaves, depends on the relative humidity around the plant.
Hot, dry air increases transpiration significantly while cool, damp air slows transpiration naturally.
Increasing humidity levels to at least 60% (or more) reduces the pressure on new roots to perform.
2 Ways to Increase Humidity
1) Lower room temperatures. Cool air holds moisture better than warm air. As long as the root zone stays warm, air temperature can go as low as 60 degrees.
2) Put your plant(s) on a Humidity Tray. Moisture in the air increases as water in the tray evaporates.
Misting plants to increase humidity doesn't do much because the effects of misting are short lived. Unless you mist your plant every 30 minutes - around the clock - misting won't help.
Grower Tip: Don't try to increase humidity by watering your plant more! Moisture in the air (humidity) is completely different from water in the pot.