Seaweed in the garden
Seaweed in the garden
Among other things, seaweed is high in magnesium, potassium and the essential trace elements needed for living things to thrive. It is also rich in carbohydrates and growth hormones which are very soluble and readily accessible.
Being reasonably low in Nitrogen but balanced with all these other nutrients seaweed is a fantastic soil conditioner for your garden.
Seaweed tea
Kelps, in particular, are high in rooting formulas such as auxins, cytokinins and gibberellins.
These are used at the earliest stage of growth and produced within the root zone. These hormones play a massive role in the life span of the plant.
To make a tea
Step 1 - Collect freshly washed-up kelp from the lower part of the strandline; this will be slightly fresher and easier to cut.
Step 2 - Remove any plastic waste and foreign objects if mainly sandy you may want to wash, personally I don’t.
Step 3 - Roughly chop up in a bucket with garden shears, place in a bucket and cover with water.
Step 4 - Cover with a lid, label or take note of the date and leave for at least a week depending on the strength you want.
Step 5 - Strain out seaweed, store in bottles or containers with lids and keep in a cool dark place. Use within 3 months. Ensure to take note of how long seaweed was brewed as this is important when diluting before use.
Seaweed is a natural product, and nutrient levels will vary according to the season when collected and the range of seaweeds in your mix.
To Dilute: add an equal amount of water for every week brewed. I.e. if brewed for two weeks then add two parts water for 1 part tea up to a 1:10 ratio for a ten-week brew or more.
To Use: Always test on a single plant first to ensure your brew is not too strong.
Once you are sure of your mix, it can be used to water young plants and seedlings or sprayed directly onto leaves as a foliar feed.
Why use seaweed as a mulch:
Feeds the soil and holds in moisture.
Being slightly salty with jaggy edges once dried it is a natural deterrent for pests, unlike some mulches which can provide shelter for snails and slugs.
Low nitrogen content and high solubility mean it can be collected and used immediately, no need to age.
Does not contain seeds, or harbour any transmittable diseases.
It is a free and abundant resource.
Applying Mulch
Don’t leave your collected seaweed in bags for too long as it will go slimy and be challenging to handle, use within a couple of days.
Spread evenly over bare ground and directly over weeds generously, a layer of 5-6 inches is perfect.
As with all mulches leave a little room around the base of each plant, although seaweed will shrink more readily than most mulches.
Because of the shrink factor, re-apply another thick layer after about a week. After this, you should be good to go for at least a month. You will still need to pull out any aggressive weeds that have grown through, but they will be weaker by the effort and should come up easy.
Seaweed in the compost
As you would imagine, seaweed is brilliant in compost; it will help build and condition your compost, adding the trace nutrients and minerals.
Add any leftovers from mulching or tea making directly into your compost.
If you gather especially for the compost then the same as any compost ingredient it will break down faster if cut small.
Collecting seaweed for the garden
Take only washed-up seaweed for the garden, do not clear a beach of all the washed-up seaweed; it plays an integral part in the complex eco-system cycle. Amongst other things, it harbours small critters that feed marine birds and also helps to nourish and strengthen dunes.
Beware of washed-up refuse like fishing hooks etc. You may need to remove any plastic waste, and this is better to do at home as you can then dispose of it mindfully.
As with collecting fresh seaweed for the kitchen, use the take a 3rd and move onto another patch system.
When collecting seaweed for mulch, try to take from the mid-point of the strandline as it will be drier and more comfortable to carry. It will also have started to break down, making it easier to spread on the garden. Larger kelp fronds are challenging to lay around plants and will take a long time to break down although good for a tea.
Onion sacks, woven poly garden bags or buckets are best. Plastics bag are difficult to handle when wet or can rip with dried seaweed.
Now you know what to do on that stroll!
Please be respectful of the environment and also keep yourself safe.