Author Archives: Paul Fisher

About Paul Fisher

Paul Fisher is an associate professor and Extension specialist in the Environmental Horticulture Department at the University of Florida. You can eMail him at

Understanding Plant Nutrition: Fertilizers And Media pH

Choosing fertilizers can be one of the most important decisions you can make for managing the media pH of container grown crops. It is therefore important to understand how fertilizers raise or lower media pH, which results largely from the form of fertilizer nitrogen (ammoniacal, nitrate or urea). This article will help you understand why

The Most Profitable Liner Size?

Should you purchase rooted cuttings in small, medium or large liners to grow on in finished containers? Our research to address this question is based on calibrachoa liners produced by eight commercial growers and research greenhouses in Colorado, Michigan, New Hampshire and New Jersey as part of the Young Plant Research Center program. Mini liners (144-count

Fungus Gnat Management

Fungus gnats (Bradysia spp.) are major insect pests of greenhouse crops and can cause economic losses across a wide range of crops during stock plant, propagation and finished plant production. Female fungus gnat adults lay eggs in growing media, and the emerging larvae feed on the roots and crown. Fungus gnat management is an ongoing focus

Fertilizing Containers

After water management, fertilization is the next most common problem with keeping large containerized plants alive through the summer. Most consumers do not fertilize their plants, or if they do, they don’t apply a sufficient amount to maintain the plants at good quality. In this article, we give specific recommendations about fertilizing of 10-inch baskets.

Improving Rewetting

  Once mixed containers or baskets are sold to a customer, their subsequent watering greatly affects the “use by” date of the plant product and overall consumer satisfaction. How easily the medium rewets is a key to your consumer’s success. It may be unrealistic to educate all our customers to become expert irrigators. If water runs

Consumer Education On Plant Care

If gardeners are broken down into segments, one segment will try to get as much information about the plants they purchase as possible. They are the customers who purchase gardening books, participate in Master Gardener workshops or check for further information on your Web site. The second (and probably much larger) segment of gardeners don’t

Combining Plants Based On Tolerances

Plants may look good together in combination baskets, however the success of a mixed container depends on more than just aesthetics. Picking plants that grow well together is essential to avoid consumer dissatisfaction. You will also save employee time at retail answering why a given plant in the combo died and how the retailer should

Understanding Plant Nutrition: Limestone and pH

In last month’s article, we stated that cation exchange capacity (CEC) does not play an important role in pH, calcium and magnesium buffering. The question should then be asked: Is growing in a soilless media similar to hydroponics when it comes to pH or nutritional management? Growing in a soilless root medium is not the

Retaining Water For Healthy Plants

Your choice of growing medium and its water release characteristics are important for your customers’ success with their patio containers and baskets. The key concept is that available water-holding capacity is not the only factor in influencing how long plants go between watering. Materials such as finer, more degraded peats, clays and superabsorbent gels can

Producing Consumer-Friendly Baskets

Plants produced in hanging baskets and large pots have become very important for spring and summer production in many greenhouses. However, consumers and retailers have many challenges keeping containerized plants alive for any length of time. Problems often come down to keeping the plants watered and fertilized. Growers have come under pressure to improve the