Want to get even more nutrients into your compost? Well, consider adding herbs. Of course, herbs won’t form the majority of your compost pile, but are a welcome addition for the benefits they bring. Think of them as you do herbs in cooking – as a little addition to add some extra zing. Below are some herbs that make great supplements to your compost, but first you need a compost pile to add them to.
Get the Basics Right
Before you get to the herbs, you need to get the basics of your compost sorted. You’ll need straw, wood chippings, pruning and branches – you’re carbon-providing elements and should form the bulk of your compost. You’ll also need green garden waste, like grass clippings, leaves and weeds. Add kitchen scraps, some soil, manure and shredded paper, keep moist and turn regularly, and you have the perfect conditions for bacteria and microorganisms to break down the material and create nutrient-rich compost. Adding herbs will both help the decomposition process and get more nutrients in there.
Comfrey is a nutrient powerhouse. It has very deep roots – sometimes stretching down as far as ten feet – meaning that it can access a lot of nutrients in the soil. It then stores these in its large, hairy leaves. When the comfrey plant is cut, these leaves break down very fast. This means that comfrey works well as a ‘cut and leave’ mulch, but can be even more beneficial when added to the compost pile. The large amount of nutrients comfrey supplies boosts the decomposition rate and serves to enrich the whole heap. (It is particularly good for ‘kick starting’ a new compost pile.) It also has a high carbon to nitrogen ratio, making compost that has comfrey in very good for plants. If you were only going to add one herb to your compost, you’d probably make it comfrey.
Like comfrey, borage produces a lot of biomass above the ground, so is an ideal crop to grow for composting or mulch. An efficient fixer of nitrogen – absorbing the element from the air and storing it in their root nodules – borage is also an excellent source of zinc and potassium, both important for plant growth.
Yarrow is a useful plant in the ground. It is particularly well suited to planting in a guild with aromatic herbs, such as thyme, rosemary and basil. The proximity of the yarrow seems to help increase the production of essential oils in the herbs, making them more resistant to damage by insects. The herbs also benefit for the high level of nitrogen in yarrow, and it is this that makes it ideal for the compost pile. Unattended, yarrow can spread quickly, so cut and prune regularly, and add the clippings to your compost.
Dandelions are powerhouses when it comes to minerals. They contain good levels of iron, calcium, phosphorus, magnesium, and copper, so composting them makes a lot of sense. They are also blessed with a lot of silica, which plants use to build strong cell walls, and potassium, which they store in their roots. Returning all these nutrients to the soil will make your plants sturdy and productive.
Nettles are another good plant to help get a compost pile going. This is primarily due to the high levels of nitrogen that they contain. But that’s not the only nutrient they bring to the mix. Nettles are high in phosphorous and iron, which is essential for the formation of chlorophyll in plants.
Chamomile may be a relaxant when brewed in tea, but added to a compost pile, it really gets things going. Chamomile contains good levels of calcium, which helps the cell walls of plants develop well and helps them absorb nitrogen. It is also a good provider of sulfur, which is one of the macronutrients essential to healthy plant growth. Sulfur promotes enzyme activity, improves root and seed production, helps plants develop proteins and increase their ability to resist the cold.
Compost piles love lovage. This is because it provides high levels of two of the most important nutrients for plant growth: nitrogen and phosphorous. Adding lovage cuttings to your compost pile will give it real boost, particularly in the early stages.
While fennel adds a lovely piquancy to food when used in the kitchen, in the compost pile it is no less dynamic. Besides lots of potassium, fennel is also a good source of copper. This trace element helps plants reproduce, so getting some into your compost will help increase the productivity of your garden.
This hardy perennial of an herb is good for adding to a compost pile due to the amount of potassium concentrated within it. One of the nutrients that plants absorb the most of, potassium builds protein, helps with the process of photosynthesis and is important in enabling plants to combat disease. This big dose of potassium makes tansy, like lovage and comfrey, a good ‘accelerator’ for your compost pile, speeding up decomposition by the microorganisms.
One to Avoid: Fresh Mint
If you have a lot of mint that you want to recycle, adding it straight to the compost pile is not the best way to go about it. Mint is a herb that is renowned for its ability to colonize areas and added to the compost pile it is likely to lead to it growing and infiltrating the compost. Then, when you spread the compost on your beds, the mint will gain a foothold and spread like wildfire, which can be detrimental to other plants. The best thing to do with areas of mint you want to get rid of is sheet mulch over the top. If you are unable to do so, you can add mint cuttings to compost but only if they are dead. Either place them in direct sunlight or wrap in a plastic bag to deprive them of light, and in a week or two they should be okay to compost.