How to Grow Plants for Oil
In this article, we’ll discuss three different plant crops to grow in your garden and how to produce your own oil. You might think it’s not worth growing your own oil, or that you’d need to harvest too much fruit to make it worth it. Fact is, however, that most oil crops have an oil content of 6-30%. Just imagine a bucket full of sunflower seeds. A third of that bucket is oil!
The first plant is the Olive, probably the most well-known oil crop. The humble Olive is surprisingly easy to grow and making your own olive oil is not particularly difficult, although it can be time-intensive.
Olives for Oil
Olives are incredibly versatile. You will be able to extract your own olive oil from them, as well as make pickled olives or preserved olives. They are a great self-sufficiency crop as the resulting product is healthy and can be preserved for years.
How to Grow Olives (Olea europea)
Did you know the ‘Olea’ is the ancient Roman word for oil?
Olives are Mediterranean natives. They are incredibly hardy and will grow in places where other plants don’t grow. They need a hot, dry climate (similar to a mediterranean climate) and, although they will grow on any rocky, dry hillside, they will grow faster in good, deep soil, with adequate water.
Olives love sun, so plant them 7-8m apart. You don’t have to prune olives, but if you see fruit production start to slow down, give them a light prune to encourage wood growth, which will, in turn, give you more fruit.
Fruiting will start after 3-7 years, but full production is not reached until they are at least 15, sometimes 50, years old. They’re incredibly long-lived; possibly as much as 2000 years old! Every Olive tree in full production will yield around 50kg of fruit.
Olives are picked at varying stages of ripeness, for a variety of processes. For olive oil, select ripe (black) or nearly ripe olives, including the ones fallen on the ground. You don’t need to pick the fruit by hand; just shake the tree and the ripe fruit will fall on the ground. If you place a tarpaulin underneath, you can easily gather the fruit.
You can read more about growing olives as a staple crop for self-sufficient gardens here: https://www.outdoorhappens.com/5-best-staple-vegetables-for-edible-self-sufficient-gardens/
Making Olive Oil
Olives will need to be crushed before you can press them for oil. You can use a coffee grinder for this purpose, a blender, a meat mill, or even a hammer (gets messy!). If you are going to produce oil regularly, invest in a small crusher (like a rock or bone crusher), it’ll be worth it.
Once thoroughly crushed, put them in a canvas sack or strong pillowcase. Only half-fill it, so you have room to close the bag and it doesn’t all spill out. Put your sack in a press. You can make your own with a barrel and a screw-down mechanism or buy one fairly cheaply. You can also press it the traditional way by covering a small table or with a plastic cloth, making sure that you prop the cloth up along the sides, so you don’t lose your oil.
Put the sack of olive pulp on the plastic and cover it with a piece of solid wood or metal. Put a very heavy stone, or something similar, on top and leave it overnight. You can also try pressing the top down with levers or jacks.
A black juice will be pressed out. Once the juice stops running, pour boiling water onto the sack, just enough to make it wet. Press it again. Repeat this process three or four times, until the juice comes out clear.
Transfer all the liquid to jars, and the oil will float to the top overnight. Separate the oil from the juice as soon as possible, strain it through very fine cheesecloth or tea towel, and seal it into clean jars.
2. Sunflowers for Oil
Sunflowers’ Latin name, Helianthus, literally means "sun (helios) flower (anthos)”. They are fast-growing annuals with huge, beautiful flowers.
How to Grow Sunflowers (Helianthus annuus)
Sunflowers are annuals, so you’ll need to re-sow them every year. They will grow up to 3m tall and will need adequate sunshine to make sure they don’t grow leggy and fall over. Even still, some may need support to keep them upright.
Grow sunflowers from seed. They germinate easily, as long as they are kept moist and are protected from birds and other animals; there are many that love eating sunflower seed! Seed can be sown straight into the garden. Plant them 20-40cm apart, in full sun. They will grow fine in poor soil, but again, they will grow better in rich soil with regular watering.
Once the flowers start fading, the round center will fill with black or black and white striped seeds. You can harvest when the seeds have completely filled out and the flowers start to go from yellow to brown. You can also wait for the seed heads to dry on the stalk. It is very easy to shake the seeds out that way, but some seed may fall on the ground and if you have a lot of birds around, they’ll happily clean them up for you.
Making Sunflower Oil
Thirty-five percent of sunflower seed is edible oil, which makes it a very productive crop. As with olives, sunflower seeds will need to be crushed first. You can do this in a blender or coffee grinder.
Put the crushed seed in cheesecloth and hang it over a jar. Gently squeeze until all the oil is removed. When the oil stops coming out, pour some boiling water over the seeds, leave overnight, and strain the oil off in the morning.
You can of course use presses for sunflower oil too, as described above.
3. Sesame for Oil
Sesame oil is very high in vitamin C, an anti-oxidant, so it doesn’t go rancid as quickly as other oils. It’s also low in cholesterol. If you aren’t inclined to make your own oil, you can use sesame seeds as garnish, instead of breadcrumbs, sprinkle over stir-fries, and for many other purposes.
How to Grow Sesame Seeds
Sesame (Sesamum orientale) is another tall, fast-growing annual. It grows to 1.5m tall and prefers a warm, frost-free growing season with rich, deep soil. You can grow sesame from brown, unhulled seed (not white seed).
It has white, trumpet-shaped flowers, followed by seed capsules. The seed capsules burst when they are ripe, shooting sesame seed all over the place, unless you can find a commercial variety that was specifically developed NOT to burst and scatter. Try to harvest when the seed is ripe, but just before it bursts open. A trick is to cover the capsules with plastic bags, to catch the seed when it disperses.
Making Sesame Oil
Seeds will need to be ground first, in a blender or coffee grinder. Empty the pulp onto cheesecloth, and hang it over a jar. Press gently with your hands to help it along, and leave it suspended over the jar overnight to catch every little drip.
Warning - rancid oils are bad for you. If you think your oil has gone bad, do NOT consume it!