Grateful Growers ~ Wholesale Premium Bedding Plants

Selection, Planting, and Care of Annual Bedding Color

Paul Berlind, M.S.
President / Owner
Grateful Growers, Inc.

    Color beds provide the most brilliant and eye-catching areas of a landscape. When properly planted and maintained, they add focus and great appeal to the property. But poorly performing beds are a noticeable eyesore. Understanding how to select, plant, and maintain annual color will help to make color beds a customer pleasing attraction rather than a source of complaints.

Selection of Annual Color

    Know Your Planting Beds

    Before you can make an intelligent decision of what to plant, you must first know many details about the beds they will be planted in. Perhaps the most important thing to understand is the quality of the soil you will be planting in. If the soil is not suitable, you will never get adequate performance from your plants. The only way to get a good understanding of soil quality is to get a professional soil test. This will tell you two critical details about your soil quality; pH and fertilizer or salt levels. For bedding plant, ideal soil pH is between 5.6 and 5.8. The soil pH directly affects the way plant roots take up nutrients, and affect disease causing organisms in the soil. If the pH is too low (rarely a problem in Austin area soils) it can lead to calcium or magnesium deficiencies, or manganese toxicity. The most common soil problem in the Austin area is excessive soil pH. This leads to micronutrient deficiencies and favors growth of disease causing fungi that can devastate a flower bed. It is important to remember that the pH scale is exponential. This means each increasing pH unit is ten times the previous unit. In other words, a pH of 6 is ten times more alkaline than a pH of 5, and a pH of 7 is 100 times more alkaline than a pH of 5. A soil pH of 7.0 or over is not suitable for most bedding plants, and a soil change out should be considered before planting.
Nutrient level analysis will tell you if fertilizer salts have built up in the bed over time. High fertilizer salt levels can cause fertilizer burn, and also promotes the growth of disease causing fungi. Soil tests will tell you if salt levels or pH levels are unsuitable for good plant growth.

    Secondly, you must know the sun exposure of the bed, keeping in mind that the sun is much lower in the sky in winter time than it is in the summer. This will tell you if you need to use plants that require full sun exposure (eight hours + of sun exposure), partial shade (5-6 hours of sun exposure), or full shade (less than 2 hours full sun, preferably in the morning).

    You should also know how well the flower bed drains. If drainage is poor, it will not support plants such as annual Vinca that requires drier soils. This will also affect the irrigation requirements of the beds. Beds with poor drainage should get plants with higher moisture requirements while beds with good drainage are can support plants with low moisture requirements.

    Knowing the soil quality, sun exposure, and drainage of planting beds is important before good decisions can be made on what to plant.

    Know Your Plants

    Making good plant selections also requires some knowledge about the plants themselves. You need to know the plants requirements for sun exposure, moisture, spacing, and removal of dead flowers (dead heading). Knowing flowering habits of plants will help your selections. For instance, some plants such as Snapdragons and Dianthus will have a lull in flowering during the shortest, coolest days of winter. Some plants such as Marigolds, Pentas, and Geraniums can tolerate a higher soil pH than other bedding plants. For good design, you need to know how tall the plants get, whether they are upright or trailing, and what colors they are available in. Plants should be selected accordingly for the beds and design they will be planted in. Inspect plants carefully before planting to make sure they are healthy and free of insects. Insist that your vendors provide high quality plant material.

Planting of Annual Bedding Plants

    Site Preparation

    Planting beds must be properly prepared before planting begins. This includes the complete removal of the previous season's plants, roots and all. Old plants can harbor diseases or insect eggs which may develop in the next season. Old mulch should be raked away completely before planting. It may be reused after planting, but planting into old mulch can cause fertility and moisture deficiencies. Tilling the soil is a good idea if soil is heavy, or if amendments such as peat moss are to be added. You may also till in granular or slow release fertilizers if rates are followed closely, or fertilizers may be used after planting is finished.

    Planting Annuals

    Avoid planting is saturated soils. Saturated soils clump causing air pockets and it is difficult to get good contact of the soil and root ball of the plants. It is not necessary to break up root balls of annuals unless they are very over rooted. Breaking up root balls can slow the development of the plant and allow disease organisms to move into the plant more easily. It is important to plant at the proper depth. The top of the root ball should be slightly above the soil surface leaving the crown of the plant (where the stem meets the roots) exposed above the soil. Burying the crown will expose it to excessive moisture and disease causing fungi. Handle the plants gently to avoid physical damage to the plants during planting. Breaking the crown will cause the plant to die.

    After Planting

    After the plants are planted, it is a good idea to spread a granular fungicide such as Subdue over the bed to lessen the chances of getting the two most common root diseases; Pythium and Phytophthera. A pre-emergent herbicide may be applied to reduce inevitable weed growth. If plants are to be mulched, use care not to physically damage the plants when mulching.

Maintenance of Annual Bedding Plants

    Fertilization

    Proper fertilization is essential to good performance of bedding plants. There are three ways fertilizer can be applied: slow release, granular, or water soluble. Slow release fertilizers such as Osmocote or Color Star can be incorporated into the soil at the time of planting. These types provide controlled release of nutrients lasting two to six months depending on the formulation. When using slow release fertilizers it is critical that recommended rates not be exceeded because they cannot be leached of removed from the soil, and excess fertilizer salts will remain in the beds for a long period of time adversely affecting plant growth. Granular fertilizers such as a 10-10-10 or 10-5-10 are easy to use. They can be spread over the bed with a Whirly Bird spreader. Granular fertilizers should be watered in well after application with a long irrigation cycle to get nutrients down to the root zone where the plants can take them up. Make sure the plant foliage is dry before applying granular fertilizers so concentrated salts do not stick to wet plants. Again, not exceeding recommended rates is essential to avoid burning plants. It is a good idea to use a leaf blower to lightly blow fertilizer granules off plant foliage before watering. Granular fertilizers need to be applied every two to three weeks according to label instructions. Water soluble fertilizers such as MiracleGrow applied through a hose end sprayer may be the safest way to fertilize, but require a hose bib near the planting beds which is not always available. The sprayer mixes the proper amount of water with fertilizer making it almost impossible to over fertilize. Application by this method is time consuming because it is necessary to put down enough fertilizer to reach four inches down into the soil to reach the root zone. Water soluble fertilizers need to be applied every two to three weeks. Whatever method of fertilization is chosen, it is crucial that label directions are closely followed to avoid problems. Using so called "blossom booster" fertilizers high in phosphorus are NOT recommended for bedding plants, and will cause excessive stretching of plants. Backpack sprayers such as Solo sprayers are NOT appropriate tools for fertilizer application. While occasional foliar feeding may have a place in a fertilizer program, it should never be considered the only or primary method used.

    Irrigation

    Accurate irrigation will help avoid many of the most common problems that cause the demise of bedding plants. This requires continual attention to irrigation timers and adjustments on a regular basis as weather conditions change. The ideal time to water a flower bed is when the top two to three inches of soil have dried out, just prior to the point when a plant would begin to wilt. Time between watering will vary as weather warms up or cools down, or during rainy periods. Each watering episode should be long enough for water to reach below the deepest roots. Over watering is the most frequent problem in annual beds, but this is only caused by too frequent watering. Plants can not be over watered in one watering episode. Each watering episode should be for as long as practical to get water deep into the soil. As weather warms from spring to summer, add watering time to each station before increasing frequency of watering episodes. As weather cools from summer to winter, decrease the frequency of watering events. Watering must be correlated with the drainage conditions of the plant beds. Fast draining beds will require more frequent irrigation while slow draining beds will need less frequent watering. Consistent monitoring of irrigation timers is the only way to water accurately.

    Scouting

    Inspect plants regularly and watch for signs of insect infestation or disease onset. If these problems occur, make sure to use only appropriately labeled chemicals to control.   Follow all chemical label directions carefully to avoid problems.

    Dead Heading

    Many bedding plants benefit from frequent removal of dead blossoms. For instance, Snapdragons, Marigolds, Salvia, Dianthus, and Geraniums all produce more flowers, and for a longer period of time if faded flowers are regularly removed from the plant.

    Following these guidelines for proper selection, planting, and maintenance of bedding plants will help you avoid many of the most common problems that can cause bedding plants to fail to perform. Your life will be easier and your customers will be happier if your annual flower beds provide the beautiful color show that they should.