I have had occasion to mention shading many times in reference to plants that need it under glass. We are as yet without any portable shading that can be adjusted to our commercial greenhouses. The wooden slat shading applied to some private conservatories is out of the question for the commercial man, and if expense did not forbid, it is too dense.
Many of our plants that thrive in the broad sun will burn up under unshaded glass. This last July, having occasion to remove the glass in a house to paint and reglaze, we left many plants standing on the benches fully exposed to sun and air. Among them I noticed Primula obconica and P. Forbesii and several kinds of flowering begonias. Before the glass was put on again, perhaps three weeks, the plants had made a great improvement in their growth, strong and robust. If the glass had been on without shading it would have been a different story.
We can at least use a light cloth on our frames over such plants as cyclamen and others that are much the best in frames during summer. A stout pole a little longer than the width of the frame with cheese-cloth tacked to it is easily and. quickly unrolled or rolled up.
We frequently are tardy in putting on shading and then daub on a heavy coat. Put on a thin coat where needed and add another when the sun is stronger, and if you will go to the trouble of plunging many of our common plants in refuse hops or decayed leaves, you will find their growth much better, and you can delay or dispense with shading entirely.
Supposing you have a house full of geraniums or cannas which, as soon as sold, say at the end of May or in early June, will be filled with chrysanthemums. If you shade for these plants you must certainly brush it off again for the mums, for they don't want and must not have any shade. Quite as important as putting it on early with such plants as palms and ferns is taking it off in good time. Begin at the end of August to remove the shade and by the middle of October have it all off.
We are frequently asked what is the best material. We have tried many mixtures, and best of all like naphtha and white lead without any oil. We tried common coal oil instead of naphtha, but it is too greasy. Try the mixture before you settle on the thickness of it.
We have also tried applying it with a syringe, and are entirely opposed to it. It saves labor, but you will use more material than will twice pay for the labor, and when put on with a long-handled brush it is properly done. This mixture rubs off easily when dry and the hose makes a clean job of it.