How to Grow Onions From Seed to Harvest : The Essential Guide

Onions, I think they just about go into every dish we eat, and they are what I consider a must vegetable to grow. They are very easy to grow, and you can plant them just into spare spots in the garden if you don’t have the spare room to grow onions. There are many varieties of onions from brown onions, yellow and red onions, they come in many different sizes and flavours. Onions also if prepared correctly will store for up to six months, we also like to dehydrate some of our onions to turn them into onion powder.

When to Plant Your Onion Seeds

Onions seeds are a cool season crop, and we normally start our onion seeds in early March. Onions seeds germinate best when soil temperatures are between 20 to 25 degrees Celsius and take between 7 and 10 days to germinate.

How to Plant Your Onion From Seeds

Onions seeds can be direct sown or sown into seedling trays. We prefer to grow them in seedling trays or a small pot, in fact we have found the best way for planting our onion seeds is into self-watering rectangle 60 cm pot. Into this 60cm pot we sow 2 rows of onions, generally one row of white onions and one row of brown onions. The seeds can be sown really closed together as we will separate when we transplant them.

Where to Plant Onion Seedlings

Onions are best grown in full sun and like a well-draining soil that we enrich with homemade compost, manure, blood and bone, organic slow release fertilser and a good layer of mulch.

How to Plant Onion Seedlings

Once your onions seedlings have reached 10cm in height they are ready for transplanting. To transplant the onion, we remove them from the pot and wash the soil of in a bucket of water. Always leave the seedling in water until you plant so they don’t dry out. When planting a row of onion, we dig a small v shape trench the length of the row, we lay the seedling into the trench at the spacing of 10cm and cover them with soil. The plants after a few days will right themselves and begin growing upright.

Caring For Your Onions

Other than watching out for pest and disease there isn’t anything that you need to do other than sit back and enjoy your garden.

When to Pick Your Onions From Your Garden

Onions take about 130 days until they are ready to harvest. Onion for can be eaten at any stage when the bulb is big enough for you to use, however if you want to store you onions you will need to wait until the onion leaves fall over and start turning brown. Once this has happening place the onion of wire racks to dry for 3 or 4 weeks in a dry place. Once dried you can remove the leaves and store in a cool dry place with good airflow.

Common Problems With Growing Onions From Seed

We have had any issue with onions except a few snails and slugs.

Snails and Slugs

Snails and slugs left uncontrolled can do a lot of damage to your garden, we generally just regularly go a pick the snails and slugs off and dispose of them. If you’re having a problem with snails and slugs here is how we control them.

Here are some other issues which you may come across but haven’t yet

Aphids

Theses are small sap sucking insect than you will find on new shoots, they are very easy to see on onions due to the style of leaves they have. Usually, you can just spray them off with a hose, however if you have a huge infestation of aphids and can’t control them you will need to spray them with a horticultural oil.

Rust

This is a fungal disease that shows up as orange to brown spots on the leaves. Prune and dispose of the affected leaves.

Thrips

These are tiny flying insect that suck the sap from your plant. The only sign they have been are silver patches on the leaves and plants not looking so great. If you suspect thrips wash the plant with a garden hose. If they appear to keep returning spray with a horticultural oil.

Bulbs Not Forming

A couple of things can cause onion bulbs not to form these are too much nitrogen, inconsistent watering and planting varieties which are not suited to your climate.