Hello and welcome back to HuwsNursery. Earthworms are the workers of the soil and are sometimes
called nature’s plow. Their job is very important for the quality of soil and also
decomposition. Many of you will think the more earthworms there are the healthier the
soil however this isn’t always the case. But as organic vegetable gardeners we encourage
an abundance of earthworms in our garden to help maintain healthy soil. There are more
than 7,000 species of them and in terms of biomass they dominate the world of soil invertebrates
and play a major role in decomposition across the globe. Their most common known job is
to recycle decaying organic matter for example eating and digesting leaves which provides
casts that contain Nitrogen, Phosphorous and Potassium which are essential nutrients for
healthy plant growth. The NPK values can range from 3-2-2 to 0.5-0.1-0.1 depending on their
diet. The castings also contain a lot of micronutrients. Earthworms also have many other benefits for
the garden. One of my personal favourite benefits of having earthworms in the garden is improving
root growth for plants. As they munch their way through the soil they leave channels of
nutrient rich casts which plant roots can follow. These channels can also create better
moisture content for soils and even improve aeration. Other benefits include mixing poor
soil with organic matter, stimulating microbial activity and better soil tilth which are all
positives for any vegetable garden. In Permaculture earthworms are possibly the biggest asset
as the worst thing is to get a dead soil where no microorganisms and earthworms are living
and working. The population of earthworms is influenced by quality of food supplies
and soil disturbance for example digging. The US department of agriculture has a list
of underlying factors which affect the abundance of earthworms which you can find the link
of in the description. So what steps can you take to increase the populations in your own
backyard? In simple terms the more fresh organic matter there is in the soil the more earthworms
there are. Adding organic matter like compost and leaf mold or mulches is the answer for
many questions for example improving soil fertility, moisture retention and in last
week’s video a better pH, however how much organic matter do I need to keep my earthworm
population thriving? It all depends on your topsoil quality however a good rule of thumb
is to easily sink your forefinger into the soil and to the knuckle. If you can do this
you will have soft and airy soil which will allow bigger vegetables as it will be easier
for them to grow and won’t be fighting compacted soil. Aim for a medium textured soil which
is preferred by earthworms. Many people say to grow vegetables you need a 50% topsoil
and 50% compost mix. Now this 50% compost mix doesn’t have to be just vegetable scrap
compost as it could also be leaf mould mixed in or mushroom compost. You don’t have to
have this ratio however if you’re just starting out or wanting to keep costs low I would recommend
starting with at least a third of growing mixture to have compost in and the rest to
be soil. Remember you don’t need to buy any compost because you can easily create
it at home. Check out this video about building soil during the autumn and winter ready for
spring. Interestingly in square foot gardening there isn’t any soil but 1 third of vermiculite,
1 third peat moss and another third blended compost but if you follow organic gardening
principles swap the peat moss with leaf mold. The mistake we made was by not covering bare
bits of ground with mulch such as fall leaves. This leaves a bare patch and will discourage
earthworms as there is no food for them to eat. Therefore ensuring that you mulch beds
particularly during the growing season and autumn will not only stop weeds from growing
but provide a great source of food for the worms. Typical mulches could be well-rotted
manure, fall leaves or grass clippings from the lawn. Another factor to an increased earthworm
population is soil depth so if you grow in raised beds on top of soil you won’t have
many problems but if it is on concrete you will expect to find fewer earthworms. To compensate
the lower numbers start a worm farm and harvest the castings and spread them round the soil
or add other cheap amendments such as compost tea, used coffee grounds and Biochar to name
a few. What do you do to keep populations of earthworms high? I’d love to know so
please tell me by posting a comment in the comments section. I have attached a few resources
in the description if you’d like to find out more and if you did enjoy this please
give this video a thumbs up. I would wish to thank Josh Sommers for allowing me to use
his close up clip of worms and you can take a look at his work on flickr. If you haven’t
already please consider joining this ever growing community by clicking the subscribe
button to stay updated with growing vegetables and learn how to grow organic produce inexpensively.
Thank you very much for watching and see you again soon!