Yam when to harvest?
Yams are nutritious, tasty, easy to cultivate, and delicious. Learn how to grow yams and add this nutritious food to your garden.
These are vines that twine with hearts-shaped, shiny, purple-tinged leaves. They develop underground from tubers that have rough skin. The flesh is more difficult to peel than the skin of a sweet potato.
They are often confused with sweet potatoes but are two different plants. With the proper planning and forethought, yams can be grown in tropical climates.
They can be planted in areas with a dry season towards the middle of June. They can be grown in full sunlight or semi-shade. However, they require a trellis. The growing season is arid, so they need lots of water.
We have included yams in every holiday feast. I can’t picture a holiday meal without a nice bowl of yams. Yams can also be steamed, mashed, or roasted and make a great side dish to the Sunday dinner.
Read more about the type of yams I like to use here: Jamaican Yellow Yams!
It is common for people to be confused by the two tubers. They have different appearances and tastes. Here are the main variations:
Yams do not thrive in temperatures that are cold. Planting them in the middle of spring is thought to be optimal.
Yams require a very long growing period, so ensure that you don’t wait too long to plant your garden in the spring or summer months. Plant outdoors after the last frost is gone and the temperature stays over 80 degrees.
In areas with frost-prone zones, it is possible to harvest at the time of the first frost since the cold enhances the flavour and sweetness.
Yams prefer soil that is loose and has adequate drainage. Expert farmers recommend testing the soil prior to planting because sweet potatoes like pH levels between 5.0 and 6.5.
Get rid of plants, debris, and stones from the soil. Include at least 1″ compost, and then dig into the depth at 12 inches.
Yams are among the most productive and easy plant tubers you can cultivate. It is possible to start with your plants or even slips.
Yams don’t come from seeds, as do other vegetables. They develop from slips, which originate from the seeds of adult yams.
Check that the yam you choose is healthy. If you notice discoloration or spots on your skin, your yam might be ill, meaning the sprouts may also be afflicted.
The watering of plants needs to be done a lot. The plants that have been planted from scratch must be watered regularly for the first week and on alternate days during the following week.
The amount of watering can be decreased depending on the increase. Be careful when you’re hydrating them.
Also, ensure that you do not overwater them, which can cause the water to collect. They can thrive in sunlight. If you observe that your soil is dry, alter the watering frequency according to your needs.
The plants need to be fertilized. Use fertilizer during the growing season to assist in the growth of production.
Purchase a fertilizer with less nitrogen in it as it is a chemical that can cause harm to the growth of roots and has a high quantity of phosphorus. It is considered optimal to fertilize your plants every two weeks or four weeks.
The yam vines aren’t strong enough and will require some form of support to ensure an acceptable yield.
Keep an eye on the plants and ensure that you stake mounds every four weeks following the appearance of the plants for the very first time. Use bamboo canes to support the vines that will grow to 10 feet.
These plants are highly susceptible to frost or freezing. Yams require an entire year free of frost and warmth. They can only be grown in subtropical and tropical areas.
Yams may take up 3 months to mature. They must be harvested when the top of the plant begins to change color and wilt. The harvesting process usually occurs around the beginning of autumn.
Yams need to be removed. Use pitchforks or other tools used for gardening to dig into the soil with a gentle touch and then take out the tubers beneath the soil’s surface. It is possible to begin digging at a safe distance from the working point.
You should ensure that you’re not thinking of washing your yams at the end of the harvest. Instead, you can separate your yams into baskets or boxes for curing before storage.
Curing can be completed in around two weeks. The yams must be kept in a dark and warm place with some ventilation and then left completely.
This will allow the cuts and bruises that appear on the yams to heal and seal off the bacteria that cause infection with rot.
After the yams have been harvested, you can store them for a few months. The yams need to be kept in a dry and cool place, like a cupboard in the kitchen.
Yams are an incredibly herbaceous vine that can climb over anything. Some vines can grow as tall as 8 inches per day!
The tubers can reach enormous – up to six feet tall and 150 pounds; however, most are manageable in their size.
The most appealing aspect of yams is that they need very little effort once you have planted them. You’ll get a huge and delicious harvest.
There are over 600 varieties of plants found throughout the tropical zones. There are a few common varieties of yams ranging from 3 to 4, which are used during cold and summertime.
Make sure to talk with the nursery in your area regarding the most suitable varieties to grow in your region.
American yams are those that are often found at the table during Thanksgiving. However, it’s sweet potato. They’re mentioned as you don’t want to get an American yam if you’re looking for a real yam.
Chinese yam is cold-tolerant, but it still needs warm temperatures. These are the most widely used kind of yam to cook traditional recipes for yams. Treat it as white potatoes and bake, roast in a casserole, or mix it into stews.
They range from white mottles with a purple hue to deep, lavender- colored flesh. Its skin can be thick as well as dark brown.
This sweet potato, which is also from South America comes under the umbrella of a yam. It is a popular food in American homes.
Make sure that the yam you select is healthy. Guinea Yams come in both yellow and white flesh varieties. They are huge yams.
The plants are afflicted with the same blights and mildew issues that tomatoes suffer from. Fungicides can help fight fungus-related illnesses. If the plant gets too large, the air circulation could be affected and increase the likelihood of developing the disease. Don’t hesitate to trim the plant to improve the circulation of air.
The Yam Mosaic Disease. Aphids cause it. This problem causes discoloration of light green and yellow in the leaves. Maintaining the area free of weeds and applying disease-free slips to stop this from happening. If you find plants with the disease, eliminate them as soon as possible.
Dry rot is a disease. This disease causes mild yellow spots on the outer skin before turning the entire yam dark. Use slips with no disease to prevent dry rot. If your yams are affected by this disease, soak them in warm water for an hour following harvest to minimize the effect.
Mealybugs. This insect resembles an oval shape that resembles cotton in colour. Mealybugs may hinder the growth of plants and also draw insects. Get rid of mealy bugs by eliminating the plants infected and then applying insecticide sprays for massive infestations.
The plants are vulnerable to many insects. The most frequent are potato grubs and yams.
Garden Insects – Identify the common insect pests and how to deal with them.
Insects with white scales. These insects form tiny white scales on the surface of yams, and they may slow the growth of yams. Treatment of plants that are infected is by using insecticidal soap.
Plant Profile
BOTANICAL Yam Name: Dioscorea alata
Common Yam Names: Chinese & White Yam;
FAMILY: Dioscoreaceae
Origin: Tropical Africa
Ideal pH of soil: 5.5 – 6.5.
Plant Maturity period: Yams 6 to 12 months.
The Plant Health Problem Common plant disease issues.
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Yams are ready to harvest as soon as their shamrock-like green tops die down, but don't rush to dig them up too soon. They don't start to fatten up until the very end of autumn and, like parsnips and swedes, their flavour will be sweeter if you wait until after the first few frosts.
Yam is the more flavored potato cousin that is quite popular on Thanksgiving. It has a nice floury texture and, whether cooked on its own or with other veggies, always adds a festive ambiance to any meal. But yam is more than just an edible veggie that makes an excellent bowl of soup.
The lush green foliage of the plant is well worth considering the next time you plan to change the landscape around you. And since it’s easy to grow and isn’t fussy about soil type or demands extra care, it’s the perfect veggie to grow and harvest.
If you’re new to growing yam, then this article is definitely for you. Here we discuss the different yam varieties you can grow in your garden, how to plant it, care for it, and finally harvest the delicious tubers.
Despite its resemblance to potatoes and sweet potatoes, yam (Dioscorea trifida) is actually a close relative of grass and lilies. A native of Africa, Asia, and America, yam was around long before potatoes made their way to the Old World on board Spanish ships. However, the majority of the 870 yam species known to science are grown in Africa.
The herbaceous vine thrives in moderate and temperate regions, and you can grow it in zones 4 to 8. And although some of those species are invasive if not downright poisonous, most of the cultivars that we list below are safe to grow and consume.
The yam vine is often large and sprawling. It can reach 6 feet high and 50 feet across. However, some species, such as the Chinese yam, grow to 9 feet high and 1.5 feet wide. As for the tubers, they usually grow deep in the soil, and you’d have to dig them up at harvest time.
When the yam tubers are ripe, the color of their skin changes to either brown or pink. The flesh inside varies from white to pink or purple, depending on the cultivar you grow. And while the tubers are the edible parts, they also moonlight as the seeds tasked with the preservation of the species. You can plant a whole tuber or just a part of it to start a new yam vine, as we’ll see later.
Choosing the right yam variety is not just about picking the one with a good flavor. It’s also about selecting a cultivar that fits in your garden and suits your zone. Here are some varieties you can grow in your garden even if you have no prior experience with yams.
You might find other “yams” in the grocery store, such as American yam and golden yam. However, and despite their name and popularity in Thanksgiving meals, these are actually sweet potatoes. Both of these veggies are the kind of variety you wouldn’t want to grow in your garden simply because they have nothing to do with yam.
There are many ways you can start yam in your garden, and they all involve using the tuber. First, you need to make sure you’re holding a yam tuber in your hand and not a sweet potato. The yam tuber is roundish, with brown or pink skin, and has firm flesh and floury texture. The sweet potato is more elongated, thin, and has white to orange flesh. Now that you’re certain that you have a yam tuber, you’re ready to plant it in your garden.
Although the process of starting yam vines from a tuber sounds involved and lengthy, it’s easy enough for any gardener to pull it off. When the plant is about 4 weeks old, you’ll need to install a stake near its base. Be careful not to damage the roots when putting down the stake. The vines will climb on the stake and spread out.
In the wild, yam practically grows in any soil type. It only draws the line at clay soil. Since the tubers grow deep in the soil, yam prefers loose and well-drained soil. This type of soil allows it to spread out and develop its robust root system and tubers without much resistance. So if you have clayish soil in your garden, you can amend it with coarse sand and plenty of organic materials to loosen it up. As for the soil pH, you will need to test it before planting the yam sprouts. If you get a reading above or below 5.5 to 6.5, then you need to amend the soil to bring it close to those levels.
One look at the dense foliage and the tubers gives you an idea of how much water yam needs. Surprisingly it’s not that much compared to plants of the same size and fruit productivity. During the first week of the yam’s sprout life, you’ll need to water it once a day. Keep the soil moist but not soaked or even wet. Once the vine starts to climb on the stake, cut back watering to once a week. The vine usually needs about one to two inches of water per week. As usual, you should factor in any rainfall in your area and adjust your watering schedule according to the amount of rain your vine gets.
Mulching is an important part of the yam vine’s growth and success. It retains the moisture in the soil and prevents weeds from growing around the vine. Yam is not very competitive, and any issues in the soil such as pests or roots of other plants would cause it plenty of distress. So lay a 3-inch thick layer of straw or hay in a circle around the vine. Don’t let the mulch touch the base of the yam since that could cause it to rot. Mulch also protects the tubers as they grow in the soil against temperature fluctuations.
If you plant yam in rich soil, then you won’t have to worry about fertilizing it. As long as the soil has plenty of organic materials, then the vine will grow at a fast rate without issues. However, poor soil impacts the growth and productivity of yam. So ensure you have mixed plenty of rotted manure or compost in the soil before planting the yam sprout. When the vine starts to climb the stake, feed it with a custom 6-12-12 fertilizer. The fertilizer should be low in nitrogen but high in phosphorus. This will encourage the vine to focus on developing tubers rather than growing lush green foliage. Add organic compost later on an as-needed basis.
Both mealybugs and white scale insects are the main bugs you have to worry about when growing yam. Mealybugs go after the sap in the leaves and spread diseases in their wake. Kill them with neem oil, or spray the vine with diluted alcohol. White scale insects, on the other hand, are attracted to the tubers. If left unchecked, they could damage the tubers and impact your crop. Use neem oil to get rid of these pests safely.
As for diseases, watch out for yam mosaic disease. It’s often spread by bacteria that aphids carry. The symptoms include lesions in mosaic patterns on the leaves, and it leaves the tubers shrunk in size and lacking starch and flavors. Remove infected leaves, keep aphids at bay, and remove any weeds around the vine.
Dry rot disease also causes lesions on the tubers. These lesions later make their way into the flesh of the tuber, causing them to crack. To prevent this disease, rub your tuber with ash before you get it to sprout. Ash kills the nematodes that cause dry rot disease.
It takes yam tubers up to 8 months from the time you start the vines to become ripe. That’s a long time for a plant to grow in the garden. Usually, by mid-fall, the yams are ready to harvest. The first sign is the leaves turning yellow and falling off the vine. Give it another couple of weeks before you start digging for the ripe tubers.
It is best to plant yams at the beginning of the rotation, as a first- year crop after clearing the land.
If yams are grown after a long fallow, they find plenty of mineral salts in the soil, and yield many good tubers.
Before planting yams, the soil must be well prepared.
- Clear the land before the rainy season. Cut down the trees, cut the branches. Stack the trees and branches and burn them.
Do not cut all the trees. Leave some of the little ones. They can be used as supports for the aerial stems of the yams. These natural supports will later be supplemented by stakes.
- Till the land to a depth of 20 to 40 centimetres.
- At this time add organic manures, well- rotted farmyard manure, compost or green manure, at 10 to 40 tons a hectare.
Inorganic fertilizers may be used to get a greater yield.
The amounts vary according to the country, region, or even the soils in the same field.
Research stations like IRAT' make a special study of food crops, and advise farmers.
In Liberia, it is known that the application of potassium (K) fertilizers is valuable in increasing yields.
In Nigeria and Ghana, the agricultural service advises that yams should be given the following fertilizers:
250 kg/ha ammonium sulphate;
65 kg/ha single superphosphate;
215 kg/ha potassium chloride.
The farmer who wants to make progress should all the time ask for advice from the agricultural service.
- In many African countries, yams are planted in mounds 30 to 40 centimetres high and 1 or 2 metres apart. These mounds are made at the beginning of the rainy season. The soil which has thus been well loosened holds plenty of water.
Sometimes the mounds are only made 2 or 3 months after planting. This earthing up encourages the development of tubers but takes a lot of work from the farmer.
If the soil is fairly deep and is deeply tilled, it is not always necessary to make mounds. In that case, more tubers can be planted and the density is greater.
Yams are planted at the beginning of the rainy season. Plant them 5 to 10 centimetres deep 1 metre apart in all directions or 90 centimetres by 1 metre. This gives the tubers plenty of room to fatten up, and the plant makes use of all the rainy season water.
Many kinds of yam bear flowers which fruit and produce seeds. So it is possible to obtain new yam plants by sowing these seeds.
But this way of propagating is no use to the farmer. The new plants grown from seed are not always like the parent plants. Often the yield is less, the tubers are much too small and of bad quality and contain a poison called dioscorine.
For all these reasons, it is better to propagate by cuttings. But here care is needed Take cuttings from ripe tubers, and not from the aerial stems, as is done with cassava. These root cuttings make plants which are like the parent plant, and give good yields.
For the cuttings use pieces of tuber or small whole tubers. To get regular sprouting and good yields, the cuttings "whether whole tubers or pieces) should weigh between 250 and 400 grammes.
The amount of yams planted represents a considerable part (about a quarter) of the harvest. That much of the harvest must be set aside and well stored for use in planting later.
Plant only fully ripe tubers. It is best to use the part of the tuber nearest the crown. This top of the tuber contains many growth buds and shoots more quickly than the rest of the tuber. For this reason, tops of tubers must all be planted in the same field.
The remaining yam tubers are planted in another field. They sprout less quickly.
With the Dioscorea bulbifera variety of yams, the bulbils can be planted in the same way as tubers. Wait until they are quite ripe, when they are easily removed from the stem.
Do not plant tubers or bulbils that are damaged, rotten or diseased.
The bulbils, pieces of tuber or small tubers are planted in the top of the mound at a depth of 5 to 10 centimetres, and covered with soil. When there is too much sun or the light is too strong, cover the mound with grass, so that the sun will not dry out the young plant and the rain will not wash away the soil and the tubers
- In savanna country where there is a long dry period, stakes are not used.
The aerial stems trail on the ground. By covering it, they prevent weeds growing, and protect it against dryness.
CONTROL OF WEEDS
For a good harvest, hoeing must be done two or three times during the early stages of growth.
When this cultivation is being done, the mounds are remade at the same time.
Later, the abundant vegetation of the yams prevents the growth of weeds.
It is then not necessary to hoe.
CONTROL OF DISEASES AND PESTS
Yams have few diseases.
However, rodents, some insects and fungi cause damage.
Damaged tubers rot quickly and cannot be kept for long.
HARVESTING
Depending on the variety, yams are harvested 6 to 12 months after planting. Lift the tubers when the leaves and stems turn yellow and dry.
Do not leave the ripe tubers too long in the ground, otherwise they become bitter and may rot.
With some varieties, only one crop is harvested. Others are harvested twice.
At the first harvest, after 6 months, the biggest tubers are lifted.
The second harvest is taken 3 to 6 months after the first.
Or the crop may be harvested as and when needed.
STORING
Early varieties, such as lokpa, do not store well. These yams should be eaten immediately after lifting.
Late varieties, such as Dioscorea alata, may be stored for 5 or 6 months.
But they must be kept dry and protected from rats and other rodents.
Yams (oca) are the easiest crop I’ve ever grown. No issues with pest or disease, and once they are planted – you can pretty much forget about them. The only negative is that they are in the ground for a long time, so if you are short on space plant them beneath fruit trees, in flower gardens or perennial edges. Smaller gardens can grow them in containers.
If you live somewhere hot – grow them in the semi shade. A win for cool gardens, they prefer us!
I start my yams in pots in the greenhouse in October because they need 18° C and my soils generally aren’t warm enough. This gives me a good headstart.
Fill a pot a third with potting mix, pop in the yam, then top up with mix. If soils at your place are warm enough, then you can skip this faffing about and plant them direct into the garden.
Keep them moist and leave them to sprout away until risk of frost has passed and soils hit 18° C.
A bed of good compost is all you need. Don’t go nuts on foliage producing fertiliser. Free drainage is more important – make a raised row if your soil is heavy clay or poorly drained.
Use an organic yam for seed or find seed online. Sethas Seeds sell Henry Harringtons yam – my favs!, especially the yellow ones.
Plant tubers at 5cm deep. If planting your potted yams, just plant to the same depth they were in the pot. A generous 40 cm spacing will bring nice fat yams.
Water during dry spells – they hate to dry out. Mulch is your saving grace, keep it topped up. A living mulch works really well, especially in hot places where tall flowers and crops will shade and cool.
You can leave yams to naturalise and become part of your herbal ley or living mulch. In this case, though you’ll only reap the odd good sized one – most will be small. Tiny even.
Yams fatten up from autumn, so don’t rush in to harvest. Wait for the foliage to die off first, or even better leave them until after a frost because they fatten and, like parsnips, become sweeter. Either leave them in the ground and harvest as required or dig up all the tubers and leave them to dry on a wire rack or basket before storing.
Along with all your good sized yams you’ll get plenty small ones. Its just how it is. Pigs love them and great news is, small ones are perfect for next years seed.
