Remember how you stepped into your greenhouse one cold, snowy day last January, and the warm, moist atmosphere and freshness of green, growing things made you catch your breath?
With shading and proper ventilation, you can make your greenhouse almost as pleasant in the summer.
If you live where summer temperatures soar into a dry heat that burns everything it touches, especially the tender leaves of greenhouse plants, then an evaporative air cooler is a wise investment.
Cooling A Greenhouse
A complete discussion about cooling a greenhouse would take more space than I can give in a column read by many who must confine their indoor gardening to a window sill or a fluorescent light set-up.
Therefore, we have made available for those who need the information a bulletin, “Shading, Ventilating and Cooling the Home Greenhouse.”
This helpful information was prepared by Charles H. Sherwood of Iowa State College, Allen H. Fairbank of the George J. Ball Company, West Chicago, Illinois, and Kenneth W. Fielder, successful home greenhouse operator of Tulsa, Oklahoma.
This bulletin is free for the asking. A four-cent stamp would be appreciated, but you need not send a reply envelope. Instead, address your request to Elvin McDonald. Flower & Garden Magazine, 543 Westport Road, Kansas City Il, Missouri.
Two Look-Alike Plants
At first glance, the plants in the picture look a lot alike. Both grow low and spread, with dark leaves strikingly marked at the veins and yellow flowers. Both come to us from Peru and have the same cultural preferences.
Both are members of the acanthus family—and are related to the more frequently grown crossandra, beloperone (shrimp plant), and fittonia.
Actually, on close inspection, each of these plants has its kind of beauty.
Chamaeranthemum Igneum
Chamaeranthemum igneum, the plant in the picture’s foreground, is the smaller of the two. Its long oval leaves have the texture of fine suede, the color of a ripe avocado toned down with a hint of brown.
The veins are bold and bright yellow, making an eye-catching feather pattern against the dark background. The plant branches freely as it spreads and seldom tops 4″ inches in height.
Stenandrium Lindenii
Stenandrium lindenii, the plant in the back, grows larger—but spreads similarly. The leaves are almost tissue-thin, with a metallic lacquered sheen.
The color is burnished copper over the green, surprisingly plum-colored underneath. Three-inch spikes sport lemon yellow flowers.
Foliage Plants To Grow In Warm Greenhouse
These are unusual and fascinating foliage plants to grow in a warm greenhouse, in tinder artificial light, in a terrarium, or in a warm but not-too-sunny window garden.
Any light, porous soil mixture suits them well if it has a plentiful supply of humus to keep it light and to hold moisture.
The soil should be kept constantly moist but not soggy wet. Keep the air humid around the plants, and the temperature always be above 70° degrees Fahrenheit.
Provide good light and some sunlight, but not so hot that it crisps the tender leaf edges.
During the warm summer months, both plants are happy outdoors in a moist, shaded, protected part of the garden. They should be brought indoors before frost.
Camellias
For several years, I have been caring for a potted camellia. During the summer months, I planted potted plants in the garden.
It grows very little and puts out buds for blooming, but when brought into the house for winter, the leaves drop off, and the buds blast.
Would you give me some information on the care of the camellia plant? Mrs. C. W. M., Maryland. The nicest house-grown camellias I have ever seen grew on an unheated sun porch.
Growing Conditions of The Sun Porch
Perhaps if I describe the light, temperature, moisture, and other growing conditions of this sun porch, you will be able to duplicate them for your camellia.
Beginning in November, the nighttime temperature is between 45° and 55° degrees Fahrenheit—sometimes a little lower than 45° degrees Fahrenheit.
The sun porch faces east and receives some sun from the south. However, large trees provide a certain amount of shade, even in the winter.
An acid soil that tests between pH 4 and 5 is used, composed of equal parts of peat moss, compost (or good garden loam), and sand.
The sun porch has a relative humidity of 50% percent most of the time. This is maintained by growing other cool-loving plants set in trays of moist vermiculite or pebbles on the sun porch.
In addition to these trays that provide moisture, the foliage and buds of the camellias are syringed once or twice a day with water up until blooming. These tubbed camellias spend the summer outdoors under the shade of high trees.
They are syringed down daily with water from the hose. A close watch is kept for such insects as a red spider, scale, and mealybug. If they attack, an insecticide is used immediately, following the manufacturer’s directions.
Repotting Before Spring
Repotting is done just before growth starts in the spring. If a plant does not need repotting, some topsoils are removed and replaced with new ones.
In the spring, a fertilizer packaged for acid-loving plants is used sparingly. Pruning is also done in the spring, after flowering.
Tips For Successful Camellias
Here are some other tips for success with camellias:
- High or fluctuating temperatures, and drafts can cause bud-drop
- Aluminum sulfate may be used to increase the acidity of the soil. It may be applied by adding one ounce to a gallon of water.
- To get specimen blooms, pinch off all the buds except one in each cluster. This should be done when the buds are still small.
- If you have no sun porch, perhaps you have a cool bay window that would be equally suitable.
- Don’t be discouraged by reading all these requirements! Once you succeed, camellia culture will seem A-B-C simple. I can think of no plant more rewarding than the camellia.
House And Greenhouse Checklist for May
Cinerarias planted now should begin to bloom early next winter. Unless you have a large greenhouse, limit yourself to growing a few plants of one of the dwarf strains, such as Hansa, Erfort, or Park’s nana multiflora hybrida. Moreover, Cineraria seeds germinate quickly.
- Transplant to 2 ½” or 3-inch pots as soon as the seedlings can be handled. Be certain that the soil never dries out.
- During the hottest part of summer, provide full shade during the day’s heat.
- As soon as you find roots coming out the drainage holes of the pots, transplant to 5- or 6-inch pots.
- A soil composed of equal parts garden loam, sand, and leaf mold is satisfactory. If you mix your soil, add a 3-inch potful of 4-12-4 fertilizer to each bushel of the mixture.
- Apply a dilute liquid houseplant fertilizer every other week. When you start the heat in your greenhouse in the fall, remember that cinerarias like a night temperature between 45° and 50° degrees Fahrenheit.
Cool Place For Summer
It’s time to sow seeds of these primroses: P. sinensis, obronica, and malacoides. First, they need a shaded, cool place through the summer.
If you don’t get the seeds planted by late May, wait until the weather cools in late August or early September.
Obconica is happy with a night temperature of 45° degrees Fahrenheit, increased to 50° or 52° degrees Fahrenheit at flowering time.
On the other hand, malacoides like to be chilly, from 45° down to 40° degrees Fahrenheit. Unfortunately, temperatures such as these are next to impossible in most home greenhouses until cold weather settles in.
Do the best you can with the temperature requirements, and if your low isn’t low enough, then perhaps you are trying to grow something you shouldn’t.
Ideal Soil For Sowing Seeds
A sifted soil composed of equal parts fine leaf mold, sand, and garden loam may be used for sowing the seeds.
Cover them slightly or not, and keep them moist throughout germination. Slip the seed container into a polyethylene bag to keep the soil moist.
Transplant the seedlings 2” x 2” inches apart in a flat as soon as you can handle them.
When the crowd, move to 4- or 5-inch pots. Obconica is said to cause a skin rash which, according to the Ball Red Book (a cultural guide for florists), can be relieved by soaking the affected parts in hot water for an hour; a teaspoon of salt, either table or Epsom, per pint of water, is helpful.
From painful experience, I know some people are allergic to malacoides. So if you get primrose rash one time, be rubber-gloved in your future dealings with all of them.
A sowing of asters in late May will give September-October flowers in the sunny greenhouse.
Potted Azaleas
Potted azaleas, indoors or outdoors in the summer, appreciate plenty of moisture at their roots and in the air around them.
They must have well-drained soil (some growers use pure peat moss) so that plenty of water can be applied and not cause water-logging.
Azaleas that grow where the atmosphere is dry are almost sure to have red spider mites, so keep the soil around your azaleas moist, and don’t let the soil in their pots dry out.
If you live north of Memphis, prune lightly until July 1 to keep the bush shapely and to encourage new growth; in the South, stop pruning and pinching by early June.
Seeds Of Amaryllis
The papery, black, penny-size amaryllis seeds are usually ripe at this time of the year. Some of those offered by mail of the finest Dutch hybrids are expensive but worth your dollar and your while growing them.
Amaryllis sometimes flower in 18 months from seeds, but it is more likely to take them two years or more. The seeds germinate best when they are fresh and when the weather is warm. Use sandy soil for planting.
After it has been leveled in the container, make drills one-half inch deep with a kitchen knife.
Sow the seeds sideways (not flat on the soil) and close up the drills with your fingers, so the seeds do not show. Keep the soil moist and flat where it will be warm (70° degrees Fahrenheit).
As soon as the green, spear-like seedlings are making active growth, begin hi-weekly feedings of liquid houseplant fertilizer. Before the seedlings crowd in the community container, transplant them into individual containers.
44659 by Elvin Mcdonald