Soil Basics
An avid plant collector, Frank Burkard, Jr. who is third-generation proprietor of Burkard Nurseries in Pasadena, always searches out unusual plants for himself and his customers. He looks forward to the optimal planting opportunities that arrive with autumn. As excited as he is about the quality of the plants that he brings into the Nursery and his home, he knows that the most important condition for plant to thrive is good soil. Burkard thus always impresses on his customers this basic fact before they leave the Nursery gate with their purchases in tow. Here Burkard shares his experience on how to prepare beds for another planting season.

Burkard and his staff often give impromptu soil lessons to customers. Understanding the basics makes a difference. Different plants like different soils. Plants that need good drainage prefer sandy soils. They develop roots deep enough to withstand dryness. Others need the moisture of clay soil. They have strong roots and do not mind the extra push it takes to penetrate them. Clay (heavy), loam, and sandy (light) make the range of the soil structure, with loam being the happy medium.

According to Burkard, the soil in Pasadena mostly is composed of clay, decomposed granite, and loam. However, pockets could differ. If customers are not sure about their garden soils, Burkard recommends that they have their soils analyzed. Whether or not the garden is blessed with "good" soil, all soils need periodic amendment for them to remain hospitable to plants. One easy way to improve the soil is to add organic matter—dead plants or animal tissue. In the soil, plant and animal matter decompose into "humus," which contains sticky gums that bind soil particles together into crumbs, not densely, as with tightly packed clay, but with spaces through which water and air can pass. Thus humus helps aerate the soil, enabling it to conduct water more efficiently, retaining some for plants use, but letting the excess drain away.

Organic matters also contain important nutritional elements that plants need. In the process of decay, living things return to the soil the substances from which they were built so that other living things can use them. Soil microorganisms break down organic matter into its basic elements, in forms that can be readily absorbed by plant roots.

Organic Matters and Fertilizers
When it comes to organic matters, animal manures provide good tilth and are high in nutrients. Burkard explains that most manures contain a high percentage of nitrogen, key for leaf and stem growth, and a low percentage of phosphorus, which is important to a plant's root development. He suggests that gardeners avoid them when they want to encourage root formation but not abundant growth of stems and leaves. Most importantly, animal manures must be sufficiently decomposed; well-rotted manure is odorless and resembles dark soil. Never use manures from dogs, cats, or human for they all can transmit diseases to the soil then to people via consumption of the plants or an open wound in contact with the contaminated soil.

Another form of organic matter is plant humus. Peat or peat moss is made up of plants, usually sphagnum or other mosses, that have decomposed very slowly in boggy places. They are not to be confused with undecomposed sphagnum moss that is used to keep plants moist or to line hanging plant baskets. Burkard recommends that the peat or peat moss be moistened before it is worked into the soil. Peat humus is a more decomposed form. Although it is relatively low in nutrients, peat is most effective in lightening heavy soil. An alternative to animal manure and plant humus is bagged amendment, found at garden centers and landscape nurseries. It often contains a mixture of animal manure and plant humus.

The other component of good soil beside its structure is its fertility. Depending on one's preference, fertilizers could be obtained in organic or inorganic form. Burkard explains that nitrogen helps develop leaves and stems; phosphorus is key to root development; and potassium is essential for plant growth for resistance to disease. All are essential to the healthy growth of any plant a customer would bring home, although how much of each to apply depends on the plant.

Once the gardener determined the needs of his soil and compiled all the necessary ingredients, he is ready to amend the planting beds. The next step requires working the organic matter and fertilizer into the soil as thoroughly as possible and as deeply as necessary for the plants to be grown in the beds—about 6 inches for lawn grass and as much as 2 feet for deep-rooted perennials. With the preparation completed, Burkard advises the gardener to have an idea of the light requirement of the plant that he brings home before placing it in the appropriate area. Finally, it is important to keep the soil and new plants moist whether they are tiny vegetable, flower or grass seedling, or a recently planted shrub or tree. Try to water deeply and not to wet the leaves. However, do not waste water.

To Mulch or Not to Mulch . . .
The varieties of mulch on the market leave many gardeners confused. Mulches range from leaves to cocoa shells to shredded bark. Burkard favors mulch material that returns organic matter to the beds as it decomposes. The list of benefits is long. Mulch keeps weed down and conserves soil moisture, helping soil stay cooler in summer and warmer in winter. It attracts earthworms, which work hard to cultivate your garden soil. It prevents soil erosion. Mulch improves soil structure as well as soil fertility because the mulch decomposes and gradually works it way into the soil. It prevents plants and their fruits from being spattered by rain or water from the hose. Aesthetically, it makes clean paths and conveniently keeps mud under control.

Yet, Burkard does not hesitate to caution that not all situations would benefit from mulching. Plants that are particularly sensitive to winter moisture may rot and die of water collected around their crown. Seeded areas and young seedling cannot be mulched. Unfortunately, mulch could attract pests, providing a hiding place for slugs and snails, and rodents, all of which can do serious damage. Thus, if a gardener has problems with these and other pests, Burkard does not counsel using mulch on susceptible crops.

Frank Burkard, Jr. practices what he preaches. Seasons after seasons, he replenishes the soil in his garden, which have rewarded him, his family and friends with bountiful crops and vivid colors. For gardeners like Burkard, tending the garden is an ongoing process where the labor is worth it for the pleasures that the garden yields.