Last week George was sharing with a friend that he was honored by the Campus Master Gardener program for 20 years in the Master Gardener program and she said, “I just do not have a green thumb. All my plants turn black.” I thought about this all week and concluded that most people say this because they do not pay attention to their plants and watch them like those who do have a green thumb. But what do you need to watch for? Or, what do you need to know about the plant so you know if it's growing OK?
One of the things you need to know about your plants to keep them alive is “How much water does it need?" In an article 10 years ago, Gladys said: “A major cause of houseplant death can be blamed on water. Too much and roots rot, making them unable to send moisture to the leaves that droop first and then die. Too little and the roots cannot pick up moisture. The symptoms in both cases are the same.” Since different plants need different amounts of water, we need to know as much as possible about the plant such as:
1. What climate did they come from?
2. Are the leaves adapted for saving water or those that breathe out water vapor?
3. Is the plant sensitive to hard water, for example Bromeliads and Catcus?
4. Do you have a tropical plant that will react if you use cold water?
5. Many plants must have resting periods so will use less water and tend to get root rot during that rest period. In their natural habitat when is the rest period?
6. Do you water from above or below? If you water from below, the fertilizer salts will also move up and concentrate in the top so you need to water from above to take it back down.
Do you let water stand in the saucers? That will result in root rot.
7. Do you sprinkle from above and leave drops on the leaves? If in the sun, blotches or gray spots can appear from the calcium in the water.
8. Do you water often with just a little water? If so, the roots will stay in the damp part and never go down deep to develop well.
9. Do you always water in the same spot? If so, the roots may grow only on one side of your pot. If you forget to water and the soil has pulled back from the side of the pot, you will need to dunk the pot and all in a bucket or old dishpan until bubbles don’t appear anymore. Then let it drain.
To keep your plants alive you also need to know about feeding (nutrients). Feeding has just as many questions as there are plants, as all are so different. We are all acquainted with lawn fertilizers and know they have three basic nutrients listed: N (nitrogen), P (phosphorous) and K (potassium). But what about our garden plants and houseplants? Are all three of these nutrients needed? Again you need to know your plant. Is the plant for foliage? Is it for blooms? What kind of fertilizer does the plant really need? Is it a desert plant? Is it a bog plant? Does it like full sun or shade? Is it a fast grower or a slow grower?
Many potting soils have fertilizer in them. If you add more you will burn the roots. There are fertilizers you can buy containing all the trace elements. A number of houseplants have their own specialized food formulas such as Orchids, Bromeliads, and African Violets. Some fertilizers are labeled “for flowering plants” while other say “for foliage plants.” In general, foliage plants like high nitrogen fertilizers while flowering plants like high phosphorous fertilizers. Phosphorous is needed for flowering and production of fruit.
During long-day and high-light months (summer) the plants will be active and need high amounts of food. (When in doubt, don't fertilize.) When the days are short, with plants inside in much dimmer lighting, we generally do not feed. Fertilizing a dry pot will burn the roots. Make sure the plant has been watered well before adding fertilizer. Also don’t feed a sick plant. Find out what your plants like. Cacti don’t use much fertilizer; Roses are heavy eaters.
Next week in part #2 we will have other things you need to know about your plants such as light, temperature, and air.