A Zest for Zucchini

Limelight zucchini, Burpee Home Gardens

Take a look at this production information for several of Burpee Home Gardens’ zucchini varieties — Golden, Hybrid, Limelight and Smooth Pickin’. Grow them for retail ... and ultimately, for consumer gardening.

Culture information

• Sow seed directly into finish container.
• Time of radicle emergence (2 to 4 days).
• Soil temperature 70 to 75°F (21 to 24°C).
• Keep media very moist, near saturation.
• Seeds are to be covered.
• Soil pH 5.8 to 6.2 and soluble salts (EC) less than 0.75 mmhos/cm (2:1 extraction).
• Avoid high salts and particularly high ammonium during germination.
• Keep ammonium levels to less than 10 ppm.

After stem and cotyledon emergence (7 days):

• Soil temperature 65 to 70°F (18 to 21°C).
• Reduce moisture levels. Allow the soil to dry out slightly before watering for best rooting.
• Keep soil pH to 5.8 to 6.2 and EC to less than 0.75 mmhos/cm.
• Begin fertilizing with 50 to 75 ppm N from 14-0-14, 15-5-15 or a calcium/potassium nitrate feed once cotyledons are fully expanded.
• Alternate feed with clear water.
• Irrigate early in the day so foliage is dry by nightfall to prevent diseases.

Growing on to finish:
Growth and development after the development of true leaves (4 to 5 weeks).

Temperature:

• Night: 60 to 65°F (15 to 18°C).
• Day: 68 to 75°F (20 to 24°C).
• Allow the soil to dry thoroughly between irrigations but avoid permanent wilting to promote root growth and control shoot growth.

Light:

• Maintain light levels as high as possible while maintaining moderate temperatures.

Media:

• Use a well-drained, disease-free soilless medium with a medium initial nutrient charge and a pH of 5.8 to 6.2.

Fertilization:

• Increase feed to 100 to 150 ppm N from 20-10-20 alternating with 14-0-14, 15-0-15, 15-5-15 or other calcium/potassium nitrate fertilizer.
• Fertilize every 2 to 3 irrigations.
• If using 15-0-15, supplement with magnesium 1 to 2 times during this stage, using magnesium sulfate (16 oz/100 gal) or magnesium nitrate.
• Do not mix magnesium sulfate with calcium nitrate as precipitate will form.
• Maintain soil pH at 5.8 to 6.2.

Controlling height:

• Use DIF whenever possible, especially the first 2 hours after sunrise, to control plant height.
• Height can also be controlled by withholding fertilizer, especially phosphorous and ammonium-form nitrogen.
• Chemical PGRs cannot be used on most vegetables and herbs.

Post-production care:

Optimum temperature:

• Night: 62 to 65°F (17 to 18°C).
• Day: 65 to 70°F (18 to 21°C).
• Optimum conditions may be difficult to maintain, especially if plants are displayed outside.

Light:

• Squash prefers full sun, although partial shade may be beneficial in retail areas.

Common problems:

• Insects: Whitefly, spider mites.