HUMIDITY
In many parts of the country, high humidity is the hallmark of summer. Along with the warm temperatures, orchids simply thrive in the higher humidity outdoors. So make sure you leave your orchids outside, while you crank up the air-conditioning and cool off inside the house. If your outside humidity is very low, say below 50%, you may be better off keeping your plants inside the home where you can maintain higher humidity.

AIR MOVEMENT
The more air movement there is, the happier and healthier your orchids will be. Place them where the foliage actually rustles gently in the breeze. Air movement helps keeps leaves cool (reducing the chances of leaf burn) and also reduces the incidence of fungal and bacterial attacks. It is one of the most frequently overlooked factors in growing healthy orchids

FERTILIZER
 During summer, you can increase your fertilizer applications on many orchids, such as brassias, cymbidiums, cattleyas, vandas, and phalaenopsis to great advantage (more growth means more flowers). However, do not overfeed your orchids no matter how wonderful the weather conditions and how well they grow. Excess feeding can cause root and leaf 'burn' which can cripple your orchid. Most of the orchids we grow are epiphytes and depend upon rainfall and leaf debris for all their nutrients. There is an optimal level of fertilizer and anything beyond this will either collect in your potting mix to the detriment of your orchid, or leach out and be wasted. With warm sunny weather, however, you can water your orchids heavily to leach out any salts that have built up in your mix.