Archive for the ‘heat’ tag
Hot weather and your plants
We certainly know about hot weather down here in Houston. This is the first year I’ve lost plants to the heat, and they were lost early on.
Leaf scorch can be bacterial or it can be caused by dry windy conditions. There is no hope for plants with the bacterial leaf scorch. For those with it caused by windy, dry conditions you can help. Plants take up moisture through the roots and disperse it to the leaves where some of it is evaporated to cool the plant. On windy days more moisture is lost from the leaves. Plants need to be able to take up more moisture faster to replace it. You’ll see leaf tips turn brown and it can progress turning all the leaves all brown before stems wilt and the plant dies. More water is the answer to this. Water regularly and deeply so plants can reach water deep down in the soil.
Too much sunlight will turn your leaves from green to white. If you see leaves bleaching out provide those plants with more shade.
Fertilize less in July and Aug. The plant can’t handle the heat and new, rapid growth. I fertilize heaviest in the spring and the fall and not at all in the summer and winter. But summer thunderstorms can rapidly deplete what little nutrients we have in our soil. If you see yellow leaves with green veins add some iron and nitrogen to your soil. Half the recommended strength is best for summer fertilizing.
Mulch. Mulch greatly cuts down on water loss and it helps keep those roots just a little bit cooler. In time it will break down and add badly needed organic matter to the soil.
If plants are wilted in the afternoon and the ground is not damp, give those particular plans a deep watering with your garden hose. Let it trickle out slowly for a long time.
No matter where you live, your trees are trying to maintain a leaf temperature of about 70′F. There is every reason to think that other plants do the same. This is the temperature at which photosynthesis takes place. The control of the temperature is done through water uptake. So give your plants the water they need and keep things well mulched.
See also:
How hot weather effects plants
From Canada to Caribbean: Tree leaves control their temperature
Talk from Mercer
I attended a talk last night given by Mercer Garden’s director. It was a wonderful talk, attend it if you can. I’ve seen it offered in various places around Houston. “Turning up the heat in the garden” or “What’s hot: Preparing & Planning for Houston Heat”.
Some interesting highlights from the talk were about preparing soil and some specific plants that do well in the heat down here.
Soil prep: The clay around your home was put there by the contractor to level out the homesite and help keep your home from sinking. It might be a few inches thick or a few feet thick. There is real dirt underneath the clay. That is what you want to plant in. So rototill it up or add at least 4″ of real soil before planting.
Use pine bark mulch, not hardwood. The pine will rot and add to the soil, the hardwoods add tannic acid to the soil which poisons it for plants.
Add sharp sand ( not play sand ) to the soil to help with drainage. This is also known as masonary sand.
There were several plants recommended for Houston. I’ll just list them with short notes. Google can serve up pictures and more information if you are interested. I’ll do specific notes on the ones I add to my gardens as I add them.
Perennials & Woodies:
Calibrachoa aka Mission Bells – These want full sun, well drained soil and will bloom all summer long. They come in several colors.
Clerodendrum speciossisimum ( I really liked this one ) This is a shade loving plant, with bright deep red flowers.
Firmiana simplex aka Chinese parasol Tree
Hibiscus rosa-sinesis aka Tropical hibiscus. On hibiscus the plants with multi-colored blooms only bloom in cool weather.
Jacarana mimosifolia aka Blue Jacaranda – all legume/pea plants need excellent drainage to do well, they are very prone to rotting.
Malvaviscus mexicanus aka Mexican Turk’s Cap. This is a large evergreen that is good for hiding things like mechanical equipment. It has the oddest red flowers on it too. Prune it heavily for best flowering, which occurs in Dec. and Jan.
Lysimachia congestiflora aka Variegated Golden Globes
Phlox paniculata aka Old Fashioned garden Phlox. Be careful when buying phlox to buy only the southern varieties. Northern versions will get powdery mildew down here.
Plectranthus aka Mona Lavendar this is an ivy with purple flowers which flower all summer. It needs part shade.
Scabiosa columbaria ‘Butterfly Blue’ aka Pincushion flower, must be well drained, drought tolerant.
Scaevol ‘New Wonder’ aka Fan flower
Bamboo – Arrow, Buddha Belly, Mexican Weeping and Weavers These are all clumping bamboos so your neighbors won’t want to lynch you in a few years. They take about 3 years to reach full height. Shoots grow one year, then leaf out following year.
Gingers – Curcuma ( elata, Laddawan, Purple Prince, Rainbow and Scarlet Fever ) I really liked the rainbow one. In the cool weather the leaves turn yellow and you should cut them to the ground.
- Kaempferia ( Alva, RAven, rotunda ) These gingers will bloom all summer for you.
- Hedychium ( corrals, ‘Double Eagle’, Tara )
Vines:
Manettia inflata – a good plant for humming birds and a very delicate vine
Passiflora ( Lavendar lady, Incense )
June 2nd will be the ginger and tropical plant sale at Mercer, where all of these will be offered.
