Landscape Basics

Trees Shrubs

Natives verses exotics

Integrating Florida's native plants into your landscape can significantly reduce the amount water, fertilizer & pesticides used in maintenance. This means less time and money spent on landscaping. Less chemicals on yards equals less chemicals in storm water runoff - a leading source of pollution in Florida's waterways. Another benefit is that native plants will provide food and shelter for the local fauna.

Find your Hardiness Zone

A good place to start your quest for suitable plants for your landscape is to determine the hardiness zone you live in. There are five hardiness zones (as described by the United States Department of Agriculture or U.S.D.A.) in the southern half of Florida, these are based on the minimum average winter temperatures for each area. To determine the zone for your area, enter your zip code into the box & click go

Keep in mind that these zones are based on minimum average temperatures and that there are other factors that contribute to local growing conditions. Plants are adaptable to an extent, some more than others. Heat, humidity, proximity to the coast, exposure to wind, rainfall amounts, physical and chemical soil composition and the amount of sunlight a plant receives will also affect which ones will flourish in a particular spot.

Soil Composition & pH.

About half of South Florida consists of poorly drained, acidic sandy soil. The remainder consists of peat and other deposited organic material and in the coastal areas sandy, calcareous soils where the plant life is also subject to salt spray and/or periodic inundation of saltwater in varying degrees. These coastal soils are more alkaline in nature. Knowing your soils pH. is important because many plants are adapted to a specific range of pH. and will not flourish outside of that range.

Soil pH is measured on a scale from 0-14, with 0 being acid & 14 being alkaline. A pH of 7.0 is that of pure water and is considered neutral. Less than 7.0 is acidic, above 7.0 is alkaline.

Soil pH has a huge effect on the nutrients that are available to plants, a pH that is too high or too low causes iron, manganese as well as micronutrients to be chemically bound-up in the soil, that is they are not in a soluble form that plants can take up & use. Prime examples of this are Gardenia's and some Palm's which will develop iron chlorosis (yellowing of foliage) on alkaline soils.

Although soil pH can be amended through the application of lime to raise the pH. or the use of elemental sulfur to lower it the main idea is to utilize those plants which are adapted to existing conditions. Be sure to test soil pH before applying or re-applying either.

Water

The amount moisture a soil receives and retains is an important feature, are the areas you intend to plant perpetually wet, moist or dry? Remember that this also relates to the underlying soil rather than just the top few inches.

Sand drains fast and retains little moisture while soil with a higher organic material content will hold more water. So if you have an area that is prone to drying out too quickly, adding a small amount of peat, clay and/or composted leaf litter will help the soil hold more moisture, reducing the amount of watering required. Remember to check the soil moisture as some wilting is to be expected in new plantings and this does not automatically indicate dry soil, it is more likely that the roots are not yet established well enough to supply sufficient water to the plant. Overwatering a plant will deprive the roots of oxygen which will in turn cause them (the roots) to die.

Best Planting Practices

When you purchase plants of course you want to choose individual plants that are robust, with a good amount of healthy growth.

What many people fail to do is to check the roots of a plant. Look for roots coming out of the drainage holes of the pot, this is an indication of being root bound.

When a plant has outgrown its container the roots begin to circle, trying to expand their reach, if this continues over a long enough time the plant becomes stunted in its growth. If possible, slip the plant out of the pot. What you want to see is many fine roots, rather than a few thick ones, if you do get plants with thick encircling roots these should be removed when planting.

Following are some tips for planting trees & shrubs in a manner to insure they get off to a good start. Try to avoid planting in summer, when the high temperatures put more stress on the roots ability to supply water.

The hole should be slightly shallower than the existing root ball and 2 -3 times as wide, the root crown - that is the point where the roots start and the stem stops should be slightly elevated or even with the soil, never lower than this. If the roots are compacted it will help to gently loosen and spread them out before backfilling the hole.

Fill the hole with the original soil to a depth equal to that of the surrounding soil, adding water as you do to ensure there are no air pockets.

Build up a small ridge of soil at the perimeter of the hole, 2 - 3 inches high for small (6 - 8 ft.) plants or trees & up to 6 inches high for larger (10 - 20 ft. or more) trees, to better direct water to the root ball during the time it takes to establish the plant. (Figure1)

After planting, adding mulch to a depth of 2 - 3 inches will reduce moisture loss from  evaporation, help to mediate soil temperature and reduce weeds in the root zone, but keep it back from the trunk 6 inches or so. If needed, use stakes and/or guy wires to stabilize the plant as excessive movement will damage new root growth.

When tying guy wires or rope protect the bark of the tree with burlap or rubber tubing, sections of an old garden hose work well for this. (Figure 2)

Pruning

When you do plant it helps to do a little selective pruning, reducing the amount of foliage in turn reduces the amount of moisture lost through transpiration, this helps to prevent undue stress to the plant, which may result in wilting and die-back.

Prune deadwood, branches that rub together & branches that cross the trunk or main stem first, then if needed prune for the overall shape of trees & shrubs alike. Remember that the lowest branches should be the longest, the branches above should be progressively shorter all the way to the top! This ensures that upper branches don't shade out the lower ones.

Figure 3 shows the correct pruning angle, which is parallel to the parent branch. On larger branches cut the bulk of a limb first then make a second final cut, this will prevent a partially cut branch from pulling & tearing the bark on the main limb or trunk. You should always leave a small stub rather than trying to cut right against the parent branch to prevent damage to it & lessen the chance for infection.

Fertilizers

Native plants don't require much, if anything in the way of supplemental fertilizers when grown in their native soils. They've adapted over countless generations to use what's available in that soil.

New plantings whether native or exotic should not be fertilized for 6 weeks anyway, as it tends to create more problems than it solves. If you feel you must fertilize, use a slow release formula with low numbers, especially the nitrogen.

Fertilizing too soon after transplanting or over fertilization can easily burn tender new roots or cause a flush of new growth which those roots may have a hard time supplying with adequate water, an abundance of tender new leaves also attracts hungry bugs like a dinner bell ringing.  

When you look at fertilizer bag or box, you'll notice three numbers which indicate in order, from left to right the Nitrogen-Phosphorus-Potassium content, commonly referred to as N P K.  On the bag to the right are the corresponding numbers 15-20-10. This tells you that this formula contains, by weight, 15% nitrogen, 20% phosphorus and 10% potassium.

These are the three main nutrients that plants need, and as such are most quickly depleted from soils.

Any fertilizer containing all three is a "complete" formula. Some fertilizers only have two of these and are referred to as "incomplete". There are also "straight" fertilizers which consist of just a single element.

Other major nutrients are Calcium, Magnesium, and Sulfur. There are generally sufficient amounts of these present in the soil that adding them is not necessary, however most commercially produced mixes do contain small amounts.

Foliar application is the spraying of a dilute mixture of fertilizer onto a plants foliage. This is a temporary "quick fix" and is a method best reserved for the application of minor elements, since the minor elements are only needed in small amounts & plants are only capable of absorbing small amounts of nutrients through the leaves. If you're going to use this method note that chelated products are better absorbed.

Micronutrients, also referred to "minors", "minor elements" or "trace elements", although needed in much smaller amounts are also important to a plants health. They are - Manganese, Molybdenum, Copper, Chloride, Boron, Iron and Zinc. In most cases these can be supplied in sufficient amounts by simply adding leaf litter or grass clippings to the soil.

• Nitrogen - Increases a plants growth rate, important for healthy green foliage

• Phosphorus - Increases a plants resistance to stress, aids in the development of flowers & roots

• Potassium - Increases quality of fruit & resistance to disease

You should cut back or curtail fertilizing during times of extreme heat or drought, always make sure a plant is thoroughly watered before fertilizing.