Pineapple (Ananas comosus), a herbaceous perennial, has elongated, dark green, sharp, sword-like leaves arranged in a spiral around a central stem and a terminal inflorescence. Cone-shaped inflorescences have pale purple or red flowers. The fruit of pineapple is a seedless syncarp (an aggregate fruit) that can weigh 5 pounds or more, has a yellow peel and pleasant aroma when ripe. Adult plants may be 3 to 6 feet high and wide.
Choosing a healthy nursery plant is the first step to successfully establish and grow a productive pineapple. Nurseries grow pineapple plants in 1- to 3-gallon containers. Avoiding large pineapple plants that come in smaller containers is necessary because they may have restricted root systems, which may not grow properly after transplanting in the ground. Avoid plants with pests and diseases.
Pineapples are tropical plants; therefore, prefer warm climate. Freezing temperatures below 28 degrees F can kill them. Temperatures below 60 degrees F and above 90 degrees F may cause the plants to grow slowly. Maintain optimum temperature range between 68 and 86 degrees F.
Pineapple plants prefer well-drained, moderately fertile, sandy loam soils that have neutral to mildly acidic pH. A good light garden soil mixed with up to 30 percent well-composted organic matter or commercial potting soil will also work well.
Digging a hole three to four times the diameter and two times as deep as the container the pineapple plant came in helps loosen the soil and allows the roots to expand.
Pineapple plants require six hours of continuous, direct sun per day for best growth and fruit production. To grow indoors, using fluorescent light tubes, left on for 12 to 14 hours per day is helpful when windows do not let enough sunshine in. Reduce the fluorescent light to 10 to 11 hours per day when the plant is large enough to bear fruit. Do this until the inflorescence appears in the center.
Water regularly and allow the top 1 to 2 inches of soil to dry out between watering. Watering the plants during extended dry periods will ensure best plant growth and fruit production. Pineapple plants are tolerant to dry soils; however, the growth and fruit production will not be robust. Adding a 3-inch layer of mulch will maintain soil moisture.
Dry fertilizer mixtures containing 6 to 10 percent nitrogen (N), available phosphoric acid (P) and potassium (K), and 4 to 6 percent magnesium (Mg) give satisfactory results with pineapple plants.
Use liquid fertilizers made of mild solutions of nutrient mixes that include N-P-K and Mg to fertilize foliarly. Following the label accordingly will prevent leaf burns.
In addition, incorporating a small amount of compost and/or top soil into the soil before planting will aid in root development and improve the water- and nutrient-holding capacity of the soil.