Knowing when to fertilize citrus trees in Louisiana is the key to a healthy, productive crop. Getting the timing right ensures your trees get the nutrients they need to thrive in our unique climate, from satsumas to Meyer lemons.
This guide will walk you through the essential seasonal feeding schedule. We’ll cover what to use, how much to apply, and how to adjust for your specific tree’s age and health.
When to Fertilize Citrus Trees in Louisiana
The main feeding season for Louisiana citrus aligns with the active growing period. You should start fertilizing in late February or early March, as new growth begins. Continue applications every 6-8 weeks through early fall.
A good rule is to make your last application no later than September. This allows new growth to harden off before the first potential frost. Fertilizing too late in the year can encourage tender growth that is susceptible to cold damage.
Why Timing is Everything
Citrus trees are heavy feeders, but they can’t use nutrients effectively year-round. Feeding during dormancy (winter) is wasteful and can harm the environment. Spring and summer feeding supports critical phases:
- Blossom and Fruit Set: Early spring feeding fuels flowering.
- Fruit Development: Summer applications help fruit grow to full size.
- Tree Resilience: Proper nutrition helps trees withstand summer heat and pests.
The Essential Fertilizer Formula
Citrus trees have specific nutritional needs. In Louisiana’s typically acidic soils, a fertilizer formulated for citrus or acid-loving plants is best. Look for a ratio like 8-8-8, 13-13-13, or a citrus-specific blend.
The three numbers represent Nitrogen (N), Phosphorus (P), and Potassium (K). Nitrogen is crucial for leaf and shoot growth, which directly supports fruit production. A lack of nitrogen is a common reason for poor yields here.
Importance of Micronutrients
Beyond N-P-K, citrus trees need micronutrients like iron, zinc, and manganese. These are often included in quality “citrus special” fertilizers. Yellowing leaves with green veins can be a sign of iron deficiency, common in our soil.
How Much Fertilizer to Apply
Amount depends entirely on the tree’s age and size. More is not better—over-fertilizing can burn roots and reduce fruit quality.
- Year 1: Do not fertilize at planting. Wait until new growth appears, then apply about ½ cup of fertilizer, spread in a circle away from the trunk.
- Years 2 & 3: Apply 1-2 cups per application, increasing as the tree grows. Split the total yearly amount into 3-4 feedings.
- Mature Trees (4+ years): A general guideline is 1 pound of 8-8-8 fertilizer per year of tree age, up to a max of about 12 pounds annually. Divide this total over your 3-4 yearly applications.
Always water deeply after applying fertilizer to help move nutrients into the root zone.
Season-by-Season Feeding Schedule
Late Winter / Early Spring (Late Feb – March)
This is the most important application. It kickstarts growth after winter dormancy. Apply a full dose of your balanced citrus fertilizer as buds begin to swell.
Late Spring (May)
Apply a second dose to support expanding fruit and continued growth. If you see pale leaves, this feeding is vital.
Early Summer (June/July)
A third application supports fruit sizing and tree health during the stressful summer heat. Ensure the tree is well-watered before and after applying.
Late Summer (Early September)
This is the final feeding of the year. Use a balanced fertilizer but avoid high-nitrogen blends. The goal is to support the tree without forcing new flushes of growth.
Special Considerations for Louisiana Gardeners
Our weather and soil present unique challenges. Here’s how to adapt your fertilizing plan:
- Soil pH: Citrus prefers slightly acidic soil (pH 6.0-7.0). Test your soil every few years. If pH is too high, nutrients get locked up. Sulfur can help lower pH.
- Container Trees: Potted citrus need more frequent, lighter feedings. Use a liquid or slow-release citrus fertilizer every 4-6 weeks during the growing season.
- Heavy Rainfall: If you have excessive rain after a feeding, nutrients may leach away. You might need a small supplemental feeding a few weeks later.
- Cold Damage: If your tree suffers freeze damage, wait until new growth appears before fertilizing. The tree’s energy should go to recovery first.
Signs Your Tree Needs Help
Watch your tree’s leaves—they tell you alot. Yellowing leaves (chlorosis) often point to nitrogen or iron deficiency. Poor fruit production or small fruit can also indicate hunger.
Conversely, dark green, lush leaves with little fruit might mean too much nitrogen. Always follow label rates and adjust based on you trees performance.
What Not to Do
Avoid these common mistakes to keep your citrus happy:
- Don’t place fertilizer directly against the trunk. This can cause burn and encourage disease.
- Don’t fertilize in late fall or winter. It’s a waste and can harm the tree.
- Don’t guess on soil pH. A simple test from your parish extension office is invaluable.
- Don’t forget to water it in. Granular fertilizer needs moisture to become available to the roots.
FAQ: Feeding Your Louisiana Citrus Trees
Q: Can I use regular lawn fertilizer on my citrus tree?
A: No, it’s not recommended. Lawn fertilizers often have nutrient ratios that aren’t right for citrus and may lack essential micronutrients.
Q: Is organic fertilizer a good option?
A: Yes, options like compost, well-rotted manure, or commercial organic citrus blends work well. They release nutrients slower, so apply them a bit earlier in the season.
Q: How often should I fertilize a young citrus tree?
A> For newly planted trees, start with light feedings every 6-8 weeks during the growing season once they show new growth. Its better to under-feed than over-feed a young tree.
Q: My tree looks unhealthy. Should I fertilize it?
A: Not necessarily. First rule out other problems like over/under-watering, disease, or pests. Stressed trees can be further damaged by fertilizer. Correct the primary issue first.
Q: What’s the best fertilizer for citrus trees in pots?
A: Use a balanced, water-soluble or slow-release fertilizer made for citrus. Follow label directions for container plants, as frequency will be higher than for in-ground trees.
By following this seasonal guide, you provide your citrus trees with the steady nutrition they require. Consistent, timely feeding is one of the most impactful things you can do for a bountiful harvest of sweet, homegrown citrus. Remember to observe your tree’s response each year and adjust your plan as needed—every garden is a little bit different.