Gardening with Gary

Gardening Advice from an Expert

Fertilizers

Q. I know nothing about the various fertilizers for sale. What should I be aware of?

A. First a couple basic definitions. You will need to study and search for information on the following:

Photosynthesis - The process by which plants use the sun's light to produce food (carbohydrates).

Macronutrients - Nutrients required by plants for normal growth. Macronutrients such as nitrogen, phosphorus, and potassium are needed in large quantities by most plants.

Micronutrients - Nutrients required by plants for normal growth. Micronutrients such as iron, zinc, and manganese are needed in small quantities by most plants.

Annuals by definition are plants whose life cycle lasts only one year, from seed to blooms to seed. Removing the flowers as they fade prolongs the blooming cycle, but if left to produce seeds, many annuals will readily reseed themselves. Annuals are usually available in little starter 'six packs' or in 4 inch 'color spots'. They are an excellent way to create a great splash of summer color in the garden, or for long blooming annual baskets.

Perennials, like old friends return year after year, growing in size and stature until they reach their full maturity. Although they live on longer, many perennials lose their vigor after 3-4 years, and should be replaced. Most perennial plants may be divided to produce new plants, or they may be grown from seeds or cuttings. Perennials are available as 4 inch starters, or in gallon size or larger pots.

Optimum growth of turf, flowers, fruits, and vegetables depends on many management factors, one of which is ensuring a sufficient supply of plant nutrients. There are 16 essential elements required for plant growth: carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, zinc, copper, boron, molybdenum, and chlorine.

Plants obtain carbon, hydrogen, and oxygen from air and water. The remaining elements are derived from the soil. When the soil cannot supply the amount of these nutrients required for adequate growth, supplemental fertilizer applications become necessary. Many urban soils are disturbed during the construction process. Top soil is often scraped off and removed and, as a result, nutrient and organic matter levels are often lower in these disturbed sites than in native soils.

Adding organic matter as well as fertilizer may be necessary to improve the growth of plants on these sites. Accurate fertilizer recommendations are important, because problems can result from either inadequate or excessive fertilization. Too little fertilizer leads to poor plant growth, but too much fertilizer can also reduce plant growth and quality. In addition, excessive applications of fertilizer can be harmful to the environment. Fertilizer recommendations are based on the kinds of plants that are grown, the type of soil they are growing in, and the results of soil tests. Soil testing provides information on the availability of nutrients in the soil and is required for accurate fertilizer and lime recommendations.

Fertilizer formulated with phosphorus (P) and potassium (K) help stimulate budding and blooming in all flowering plants.

All Purpose is an ideal choice where a balanced high analysis fertilizer is required for all types of vegetation. Ideal for evergreens, flowers, shrubs, trees and vegetables. May be sprayed on with a hose-end sprayer if desired.

A preplant formula of 18 (N) & 46 (P). (18-46-0) It is broadcast on top of the dirt immediately before laying the sod at 10 Lb. per sq.ft or onto your garden beds. This cuts rooting in time by several days and encourages deep root growth.

Maintenance fertilizer is an 18-5-12 formula with 10% sulfur & 3% iron. The sulfur counters our alkaline soils and the iron helps keep a rich green color.

Assistance from article of The University of Maryland, Home and Garden Information Center.

Janet writes~ I seem to remember that you can spread used coffee grounds around certain plants. Is this a myth or which plants would benefit from doing this?

A. Coffee byproducts can be used in the garden and farm as follows: Sprinkle used grounds around plants before rain or watering, for a slow-release nitrogen. Add to compost piles to increase nitrogen balance. Coffee filters and tea bags break down rapidly during composting. Dilute with water for a gentle, fast-acting liquid fertilizer. Use about a half-pound can of wet grounds in a five-gallon bucket of water; let sit outdoors to achieve ambient temperature. Mix into soil for houseplants or new vegetable beds. Encircle the base of the plant with a coffee and eggshell barrier to repel pests. If you are into vermi-posting, feed a little bit to your worms.

Assistance: http://www.sustainableenterprises.com

After you brew your coffee, save your grounds. Put them in a canister like an ice cream bucket or coffee can. Scratch them into the soil. Coffee grounds are an excellent fertile source of organic matter of plant food. They contain about 4% nitrogen, 1% phosphorus, and 3% potassium. Just be aware, fresh coffee grounds can burn very tiny transplants, so hold off on the strong stuff when the plants are real young.

Besides vegetables, acid-loving plants like azaleas, camellias, gardenias, blueberries and conifers [as pine and spruce] can also benefit from a cup of Java grounds. You can also dilute your coffee grounds with water. This makes an excellent liquid fertilizer that's completely organic. Keep in mind, coffee grounds are acidic, so you want to be careful how much you apply to the soil. In fact, it is a good idea to have your soil tested just so you don't overfertilize.

Edited from: Rebecca's Garden

Cora writes~
Do you like those stick fertilizers? It is a nuisance for me to measure powders or liquids and to make such big quantities at once, so I usually use those sticks. Are they any good at all? They are convenient. Do you have a better idea about fertilizing? I want my plants to do as well as they can.

A. Certainly use them if they are more convenient for you and the results are good. I note that you said that your African violet was blooming, so the strips must be working fine.

My opinion has been that if some practice or ingredient works well for a grower/gardener, then stick to it. Too many people read something and feel that they should change their methods even though their plants are fine. This can lead to problems since everyone has different growing conditions and what works for one grower may be disastrous for another.

These sticks were designed for ease in supplying food for a wide range of house plants through slow release and avoiding fertilizer burn and the lack of food due to neglect. Plus, as you state, you do not have to be concerned with powders or liquids. Enjoy your method and the good results you have obtained.