70 degrees and filtered sun WHOOPEE! watch me grow
For the most part, members of the geranium family are happiest in this environment and grow like weeds. Obviously, there are some varieties that prefer other conditions and will tolerate cold and heat to considerable extremes. Some Hardy Geraniums, for example, are cold hardy to 20 degrees or lower while those same plants can withstand full sun in the central valleys and temperatures ranging upward to 100 to 110 degrees.
As a standard rule, 50% shade cloth secured overhead can provide the proper sun exposure and temperature becomes the only enemy. That’s why greenhouses and air-conditioners were invented. The rule is, don’t put a geranium in a location where you would not be comfortable yourself.
Many of the books, nurseries and magazine articles will state ‘Grow in full sun’ but those were all written from locations which have mild climates and do not apply to the Central Valleys and foothills of California.
Geraniums are just like people
They don’t like too much heat and sun combined and they don ’t care to sit outside on a frosty morning. They all have a different tolerance for sun and temperature extremes just as we do.
Grow your plants in containers so that they may be moved about to locations that offer more suitable micro climates.
I will move my plants to different locations until I notice that the variety has found a happy place. Each variety has a unique tolerance to sun and temperature and finding the right spot in your yard or greenhouse can sometimes be a bit frustrating.
Don’t forget to protect your plants from the frost. I bring mine in the house and let them watch The Garden Channel on TV when I know there is going to be a severe frost, they like that.
Variegated & Yellow/Green Leaves
Variegated plants or those having yellow/ green leaves can not tolerate the heat and sun as well as the ‘green’ leaved varieties and grow best in the cool coastal climates or air conditioned greenhouses.
These plants can be grown in the central valleys and do well from October to mid May during the cool season. the plant will ‘stress’ through the warm season and will show dried edges to the leaves and growth will slow.
Reduce the amount of fertilizer and provide shade throughout the day. The plantsare best kept in containers on the ground where air temperatures are coolest.