it's All About Sunlight

Red Buckeye - Aesculus pavia

 Last July, I wrote about the importance of sunlight and my hope that I had planted my small woodland properly to get the most out of it. As I sit here today, it looks like I have done pretty well. My once-small red buckeye is in full bloom. Last summer it went deciduous at a time that seemed far too soon, but that has happened to me before. Red buckeye abhors the intense sunlight of summer. It is a deciduous tree and it grows in the understory of deciduous woodlands. Given too much sunlight in summer and early fall, it will shed its leaves and revert back to its winter look - a bunch of stout bare stems. I planted several nearly 30 years ago in a native plant demonstration landscape at the Pinellas County Cooperative Extension office not fully understanding this. The woodland I planted consisted of 3- and 7-gallon canopy trees and I planned them to someday provide some protection for the red buckeyes I planted adjacent to them. Each year, before the canopy truly developed, the buckeyes would leaf out and then lose their leaves within weeks. The sunlight they were receiving was just too harsh - but they didn't die at least. Today, those trees are flourishing. They bloom each spring and set fruit (nuts, of course). I anticipated the same thing happening here when I planted the one I now have.

Many gardeners fail to fully understand the importance of sunlight - especially for those plants that occur naturally in understory settings. We "protect" them from sunlight as if sun was the enemy. It is not. As I've written previously, and in my book The Nature of Plants, plants feed on sunlight, not on fertilizer. Without sufficient sunlight, they will never grow or bloom properly. Protecting plants from sunlight is equivalent to starving them to death. My buckeye - and my other understory woody plants, need sun; they just need it on their terms.

Most true flowering understory woody trees and shrubs exist beneath a deciduous canopy. Leaves of the canopy trees fall off in late fall and do not return until spring. During the time in between, the understory exists in full sunlight - the very sunlight they require to survive. The sun in winter and spring produces much less light intensity than it does in the summer and early fall, but it produces sufficient light for those plants to absorb it, flower and fruit, and then store it for the next spring. My buckeye will likely shed its leaves once more this summer as my canopy trees are still relatively short, but it will bloom even heavier next year.

I have planted three species of native azaleas here as well - all native to north Florida. I used to watch them languish in former landscapes and the reason was the same as for my buckeye. They were at the edges of my live-oak canopy and they did not get sufficient sunlight in the winter and spring. As I watch the flower buds now start to swell here, I know that I was correct to have put them in the locations I did. They did not want or need protection from the sun - they just needed a lot of it at the right time of year and less later. 

There is a faction within the native plant groups I belong to that believe that natives should only be planted in their native ranges to be considered "native."  I understand that argument, but I don't adhere to it. My life and the life I am creating in my landscape are enriched significantly by my north Florida flowering trees and shrubs. They simply need a deciduous canopy; sun in the winter and more shade in the summer. It's a simple concept. Feed your plants with sunlight when they need it and back off feeding them the rest of the year. We just feed them with sunlight. I don't feed them with anything else (or water them either). As I sit here writing the flower buds on my two downy serviceberries (Amelanchier arborea) are being formed. They will be in full bloom with a week or two. The azaleas, the viburnums (I have not planted Walter's here, but the others), and the haws will follow. It is a time of year I await each year with great anticipation. After all, a landscape should bring nearly as much joy to us as it does to the wildlife we are encouraging.

Pink azalea - Rhododendron canescens

Florida flame azalea - Rhododendron austrinum