Top dressing citrus trees with compost each year is an easy way to give them a nutrient boost and prepare them to grow lots of fruit. Topping the compost with mulch will help to keep soil moisture in and keep weeds away from your citrus trees. Top dressing can also be done with a mix of aged cow manure, worm castings and pelleted chicken manure.
Citrus trees that need top dressing
Citrus trees like lemon, lime, orange and mandarin will all benefit from top dressing. These trees are heavy feeders and have small feeder roots that grow in the top 12 inches of the soil. Adding a nutrient rich top dressing of compost will quickly reach the feeder roots and boost the nutrients for the tree over the growing season.
When to top dress citrus trees
The best time to top dress citrus trees is in Spring and Fall. Top dressing can be done once per year so choose when you have time to do this process. Spring is a great time top dress citrus as they are about to move into the warmer months where they will grow more leaves and stems.
Lemon and limes which flower and fruit in Spring and Summer so spring is a perfect time to top dress these citrus trees. Oranges and mandarins grow fruit over the cooler months so set them up with extra nutrients by top dressing in Fall.
Best top dressing for citrus trees
Top dress citrus trees with compost that you have made at home. You can also use bought compost, worm castings and aged cow manure. Mix all of these ingredients together including a handful of pelleted chicken manure. This is the perfect nutrient rich mix for your citrus trees.
This combination has nitrogen for leaf growth and a mix of organic matter which will keep soil moisture in and feed soil bacteria. The soil bacteria will encourage worms which mix the organic matter through the soil. The worms will make air pockets in the soil and help the citrus tree to grow a stronger and larger roots system.
How to top dress citrus trees
Top dress citrus trees by raking back the mulch from underneath the tree. Expose the soil so that you can add the top dressing straight to the soil. Look out for worms as you rake back the mulch. This is a good indication that your soil is healthy.
Add the top dress mix of compost and aged cow manure to the surface of the soil. Rake it over flat around the root system. Do not dig the top dressing into the soil otherwise you can damage the roots. Cover the area under the leaf canopy of the citrus tree.
Rake back the mulch over the top of the added compost mix. Add extra new mulch if there is not enough to re-cover the area underneath the citrus tree.
Best mulch to use for citrus top dressing
The best mulch to add on top of the citrus top dressing is a mixed tree mulch. This is a mix of bark mulch pieces and leaf and stem pieces which will make a great mix of green and brown materials. You can also use straw, sugar cane mulch and Lucerne which will break down quicker and mix into the soil.
Watering in top dressing under citrus
It is important to water in the top dressing after adding it underneath the citrus trees. This will start the process of washing the nutrients down to the tree roots and settle the mulch in. Watering the mulch will also stop the mulch from blowing away. For more on this, check out my previous article on mulching windy spots.
Top dressing for outdoor potted plants
Top dressing for outdoor potted plants, including citrus trees is best done with home made compost. If you do not have any of this you can add an aged cow manure on top of the soil. Add ½ an inch of aged cow manure and then top straight with mulch.
You can also use bought compost for top dressing outdoor potted plants. This can be used as both a mulch and a top dressing. It will hold soil moisture in and prevent any weed seeds from growing that get blown on the surface of the soil.
Top dressing for indoor potted plants
The best top dressing for indoor potted plants is good quality potting soil. This has no smell and is rich in nutrients which will feed your indoor potted plants. You can top the potting soil with coconut fiber to stop the soil from being washed outside of the pot.
If there is not room for top dressing it may be better to re-pot your plant and replace the soil with new potting soil. For more on this check out my previous article here: How to replace soil for potted plants.
Top dressing flower beds
Top dressing flower beds is as easy as raking back any mulch on top of the soil. Adding compost, aged cow manure and pelleted chicken manure mixed together. Sprinkle it around 1 inch deep on the soil surface and around the root zone of flowers. Cover it with the mulch that was previously on the bed and add new mulch if needed.
Top dressing citrus trees – FAQ
For existing citrus trees, top dress the root zone with compost, aged cow manure and worm castings. Cover this mix with mulch like mixed tree mulch for a long lasting mulch cover. You can also top with straw or sugar cane mulch which will break down quicker and improve the soil. Make sure you cover the whole area under the tree canopy at least out to the edge of outer branches.
Top dress a fruit tree by moving mulch away from underneath the tree and trunk. Layer a 1-2 inch top dressing mix of compost and aged cow manure. Add pelleted chicken manure to the mix for an extra nitrogen boost. Cover the top dressing with mixed tree mulch.
Egg shells can add calcium to the soil for your fruit trees. Egg shells can be crushed and sprinkled around the root zone or broken down in your compost or worm farm first. The smaller the egg shell pieces, the quicker it will break down and add calcium to your soil.
Coffee grounds can add nitrogen to the soil for lemon trees bit it should be broken down in compost for 98 days before adding to the top of the soil. This will break down any chemicals in the coffee grounds and neutralize any acidity. This can then be added as a top dressing around your lemon tree under the leaf canopy
How to top dress citrus trees – Summary
Top dressing citrus trees is a great way to give your citrus trees long lasting nutrients. This can be done once per year and is a good opportunity to top up the mulch levels. Keep mulch to 2-3 inches thick to keep weeds down.
Happy top dressing.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.