If you have your own horse, you also have an endless supply of free, top-quality fertilizer. Horse manure can be an excellent fertilizer for your garden, but it is important to use the right amount. Using too much horse manure could harm your plants, while using too little could leave them without the nutrients they need. By getting the amount just right, you can grow a garden full of happy and healthy flowers, shrubs and vegetables all year.
Use Aged Manure - Use composted manure for maximum effectiveness and nutritional value. But if composted horse manure is not available, well-aged manure can be a good substitute. It is important to avoid fresh horse manure, since it could burn the plants. If you have a horse or two of your own, consider installing a couple of compost bins and using those as you clean the stalls. The manure will then compost and the finished compost can be used in your own garden, or even sold to other gardeners in the area.
Look at the Composition - It is important to look at the composition of the manure pile. If the horse manure is mixed with wood chips or sawdust, it is important to age it further before applying it to the garden. One of the best ways to speed up the aging process is to layer the manure with grass clippings -- that will help the manure break down faster and be ready to use sooner.
How Much to Use - When applying horse manure as fertilizer around the flower garden, it is best to apply it to a thickness of between 1 and 3 inches. The manure can be applied directly to the soil and mixed in to provide more nutrients and nitrogen. Horse manure is a rich source of nitrogen, an important nutrient for vegetables and flowers. Apply the horse manure at a rate of 1 lb. per square foot, mixing it in with the soil to release the nutrients the vegetables will need. Apply it at least 60 days before you plan to harvest your vegetables.