Over-watered Onion will develop yellow leaves. It is normal for yellow leaves to develop when Onion has reached the end of their blooming period. However, if the leaves turn yellow before the flowers have bloomed, it is a sign of over watering. If you water your Onion too much, then try to ensure there is adequate drainage and do not give it any more water for a couple of days. You can mix some sawdust into the soil to absorb the moisture. If the situation continues to deteriorate after controlled watering, consider whether the seedpods have rotted. Try digging them up and checking whether they have changed color and become soft. Once you find severe decay, then you should promptly clean out these seedpods. Under-watered Onion actually looks similar to over-watered Onion with their yellow leaves. However, the stems will also droop and leaves will look smaller and will curl. You may also see some brown patches appear. If you have given your Onion too little water, then do not panic. It has a level of drought tolerance. Once you have realised, give it a good drink but do not saturate the surrounding soil. Just make sure it is moist.But do not give them too much and overwater them, you just need to let the soil to be mosit. Extended periods in water can lead to root rot and fungus growing on the bulb. The fungus can cause serious damage to the bulb which is noticed through spots that appear on the leaves and buds. The tips of the leaves may also discolor and die.

It very much depends on the location and the current growth state of your Onion. Once you have planted your Onion, water them well once and then leave them. That initial watering will kick start their growth, but after that you can leave them be until you see shoots appear. If your Onion is in a pot, you will need to water them when the top 1-2inch feels dry. Container plants can dry out faster than bedded plants, so ensure that the soil is damp. If your Onion is planted outside in flower beds and borders, they will not require additional water if it has rained during the week. The Onion has some drought resistance, slight dryness can be recovered quickly after watering, but excessive watering can directly cause the plant to die once the seed ball rots, you need to stay cautious about how often you water the plant.

When your Onion is growing, you will need to water about once a week. As the temperature rises, the soil will dry out faster and you will need to increase the frequency of watering. A dry soil environment will be more friendly to your Onion than an excessively wet soil environment. Onion will become dormant during summer and the above-ground parts will completely dry up and die after dormancy,. if you planted it outdoors, you shouldn't need to water it. Moreover, if there's plenty of rain in your region, you should consider digging them out to protect the buds from rot due to too much water. If you planted it in pots, you should stop watering your Onion completely after the dormant part dries out. After the above-ground part dries out completely, dig up the buds and store them in a cool location or stop watering them completely to keep the soil dry. Resume watering until the next sowing season. Or keep them in the soil in a cool location until the next growing season.

Monitor your containers for moisture, moving them to a sheltered position if they become sodden or waterlogged. Allow them to dry out and return them when the weather improves. Outdoor planting often takes rainwater into account, and when planting, you should consider planting the plants in well-drained soil to avoid waterlogging and decay. Whether grown indoors or outdoors,before the buds grow out after planting the bulbs, they need very little water and you should try to let the soil dry out completely before watering in small amounts, which will effectively avoid bulb rot. You should wait to water them regularly until they grow new shoots. Your Onion is more susceptible to rot indoors in low light and poor ventilation. Therefore, you need to be careful when watering indoors and make sure that a lot of the soil is dry before watering. If you can keep it moist for a long time indoors, you also need to consider if your Onion is in an unsuitable location. Whereas outdoors, good ventilation and plenty of light will be relatively safe.

Pruning your Onion is a fairly simple process. First, you will need a reliable set of hand pruners or hedge trimmers. You may use a clean pair of sharp scissors if you don’t have pruners or garden shears on hand. It’s important to always clean your gardening tools before and after using them to prevent the possibility of spreading disease or infection to other plants. To prune your Onion simply allow your plant to go dormant over the Winter. Some time between late winter and early spring – or when new growth starts to appear – take your clean pruners or trimmers and cut away any dying, damaged, yellow or declining foliage. Repeat this process until you reach the base of the plant or until there are no dead pieces left to cut. When pruning, be careful not to damage the new growth that may be emerging near the base of your plant. These parts cannot be restored and pruning can increase the ventilation of the plants and facilitate their growth. Any pruning that is done to this plant should be cut straight across the blades or stems. No angled cuts are required. Diseased leaf blade foliage can be removed as it appears. This could be done anytime when your Onion is growing.

Once you’ve pruned your plant, you should dispose of the stems and leaves either by composting the healthy ones or throwing out the diseased parts. You can also fertilize just before or after pruning, which gives Onion a little vitamin boost that can provide it the nutrients needed to better protect itself from any nearby pathogens or diseases. Do not water the Onion immediately after pruning as this can lead to fungal infestation of the plants through the wounds. You don’t need much after care when you’re done pruning. It might benefit from light watering and some liquid plant food to encourage new growth.

Early spring and late winter are the best times to prune your Onion on a large scale. If you want to control the size of your Onion, you can prune them as you wish, but be careful not to prune more than a third of the size of the plant. Yellow and diseased leaves may appear during the summer months when the Onion is growing vigorously and these types of leaves need to be pruned back immediately. These parts of the Onion cannot be restored and pruning increases the ventilation of the plant and facilitates its growth.

Strategic pruning is usually done at different times of the year or during certain stages of growth depending on the plant. However, knowing when to prune your Onion depends on where you live and how established your plant is. For example, if your Onion is a new resident, it’s a good idea to wait until the plant starts to grow back before you start pruning. On the other hand, if your plant is already established, you will want to prune the dry or dead parts in plant before new leafy growth appears in early spring or late winter. This is the time of year when plants are dormant and pruning causes the least damage to them. This is also the best time of year to do more extensive pruning. It’s important to note that if Onion is pruned too late in the season, it can leave new growth at risk for damage or disease. However, if your Onion is indoors this is not a problem and you can prune at any time. Since this can affect the long-term health and appearance of your plant, it’s important to keep this in mind when deciding when and how to prune. As your Onion grows larger over time, you can trim it as needed after annual pruning. Dead, damaged, or diseased leaf blade foliage can be removed as it appears. This could be done anytime when your Onion is growing.

Exact needs vary, but a minimum of 6 to 8 hours per day is a good rule of thumb for Onion to grow and produce fruit.

Onion requires full sun, meaning that it should be grown in a location that gets direct sunlight that isn’t blocked by obstacles such as trees, fences, or buildings. In general, the faster the plant grows, the more hours of sunlight it will need. Morning sun is best for photosynthesis.

Onion should not need to be protected from the sun in most climates. Those who live in a desert or near the equator may find that the sun is too harsh for the types of plants they want to grow, but this is the exception.

All plants need sunlight to convert into energy. Plants that have a short growing season need even more light and energy than those that grow slowly, as they need to complete all their processes to grow and produce fruit within just a few months. The first symptoms of insufficient sunlight in Onion are pale and yellow leaves that are not able to generate enough chlorophyll to keep their healthy green color. The leaves may eventually fall off, and new growth is small and weak. The plant may become leggy and sparse as it stretches toward the available light. Finally, without enough light the plant will not be able to produce large, high-quality edible leaves or fruit. Onion needs to devote a lot of energy into growing leaves and fruits, so if there isn’t enough light available for it to convert, the harvest will suffer.

Onion can get sunburned from intense sunlight, especially when coupled with high temperatures and not having enough water. Afternoon sun tends to be most likely to burn plants. Scalded leaves develop faded patches of light brown to white on the areas at the top of the plant that are exposed to the most sun. They are especially vulnerable to this right after being transplanted from a shadier location to being in full sun. Transitioning plants gradually or providing them with a barrier while they are adjusting can help prevent sunscald in young plants. In many cases, Onion develops leaves that are large enough to protect fruits from the strongest rays of the sun. However, if intense sunlight is in contact with fruits, they can also be damaged. Avoid over-pruning those protective leaves so that the fruits don’t get burned.

Onion may become unbalanced if it gets significantly more light on one side than the other. Ideally, you can plant your Onion in a location away from obstacles that might block light, and where the distribution of sunlight is even on all sides. Be careful about planting tall species next to those that grow closer to the ground. It may not be obvious when the crops are first planted, but over time the taller plants may begin to block the amount of sunlight that can reach the shorter plants. Morning sun helps to dry dew and precipitation, which helps prevent infection from diseases that can develop when water sits on the plant. If you are watering or irrigating your Onion, this should be done in the morning.

There is an ideal temperature range that makes Onion feel at home. Under these temperature conditions, it's unlikely that you’ll have any issues with cold or hot damage to the foliage, but changing leaf colors can absolutely be a sign that Onion isn’t happy. Try to keep your Onion well within its preferred range of 70-85℉(21-30℃), but don’t panic if the temperature creeps up past 85℉(30℃) during the day or down to 70℉(21℃) at night.

If your Onion happens to be planted outside, then there’s not much you can do to try to move it indoors. However, you can certainly provide cover in ways that will help it survive any extreme temperatures that may arise unexpectedly. For instance, you can always use a few stakes and some cloth to put together a shade tent that will block out much of the sun’s intense heat from direct sunlight exposure. Similarly, Onion can be protected from the extreme cold and especially chilly winds by building a small greenhouse around the plant, which will create a greenhouse effect and warm the plant up. This can be done using garden stakes and any sort of clear or translucent plastic you may have around; if you have greenhouse plastic such as polycarbonate laying around, this works perfectly. Remove the greenhouse once temperatures warm up to 40℉(10℃) at night.

Generally speaking, Onion needs to stay within its preferred temperature range all year long. However, that doesn’t mean that care should stay the same all year long. During the warmest months of the year, Onion will need a little extra shade and a bit more of a breeze to help it cope with the hottest days. On the other hand, it may need to be moved away from chilly windows and doors during the cooler months in climates where temperatures drop below 40℉(10℃) at any point in the year.

Keeping your Onion at the right temperature can be fairly simple. Depending on where you grow it, Onion can be fairly easy to accommodate. For indoor growing, you can easily move the plant to different locations within your indoor space that best meet its temperature requirements. Avoid placing it near air conditioning vents, heaters, doors that open frequently, or drafty windows. It is a little more difficult to control the temperature around your Onion if it’s grown outside. Of course, if it’s planted in a pot, you can simply bring it indoors when the temperatures outside get too hot or too cold for Onion, but otherwise, you may need to take different measures to protect it from extreme heat or cold that may damage it irreversibly. Try placing Onion under cover to protect from both the harsh sun that can overheat it and any cold wind that could be potentially deadly for your plant.

Onion typically grows quickly, and uses a lot of energy to create the root vegetables we enjoy. Along with sunlight, oxygen, and water, Onion species require nutrients to grow and produce roots. While these nutrients are generally present in garden soil because of the natural organic matter decomposition in and on top of the soil, there may be some cases where the nutrients are not abundant enough to support healthy Onion growth. In these cases, fertilizer provides the boost that the Onion needs.

Apply natural fertilizer to your soil to prepare it for planting. There is no particular time frame you are required to follow, but be sure you have enough time to incorporate the fertilizer into the soil and water it thoroughly before putting seeds or seedlings in the ground. In general, one application of fertilizer is enough to keep Onion growing well throughout the season, but you can do one additional application once the seedlings have started to establish themselves if you want to boost their yield even more. Just be careful not to use too much fertilizer that could damage the plants.

Avoid fertilizing when conditions are dry, and always water plants thoroughly after fertilizing. All types of fertilizer are most effective when delivered through moist soil. Don’t use high-nitrogen fertilizers unless developing a lot of foliage is more important to you than the root crops. Be careful not to let fertilizer touch the base of the plant or splash onto leaves or stems, since this can cause the plant to burn.

Most people grow Onion in order to harvest the roots, although in many cases the foliage is also edible. To promote a healthy root system, choose a fertilizer with more phosphate and potassium compared with the amount of nitrogen. Bone meal and kelp are great choices for natural fertilizers, but chemical fertilizers can also be used. Just make sure the fertilizer doesn’t contain a large amount of nitrogen, since that is a less important nutrient for this particular vegetable. The best way to determine what type of fertilizer to use for growing Onion is to take a soil sample from the part of your garden that you are planning to use. Testing the soil will tell you which nutrients are needed, along with other important factors such as density and pH level. All of these factors contribute to your plant’s success, so it is a good idea to think of it holistically and treat the soil accordingly.

Fertilize Onion by mixing an organic fertilizer such as bone meal or kelp into the soil prior to planting. If you need to fertilize again during the season, do so by using a layer of compost or well-rotted manure as mulch around (but not touching) the base of your Onion. This material will break down gradually, allowing nutrients to soak through to the roots below. For liquid fertilizers, dilute the fertilizer with water according to the instructions for your particular crop and spray it on the ground around the Onion, being careful not to splash the plant. Granular fertilizers can be sprinkled around the base of the plant or between rows, or worked into the top layer of soil to keep the granules from being washed or blown away.

Too much fertilizer (especially chemical fertilizer) causes the plant to become stressed. Fertilizer burn is caused by excess salts that are contained in chemicals, which can dehydrate plant cells and cause yellowing and wilted foliage. Be aware that fertilizer burn symptoms can also look very similar to other issues including nutrient deficiency, so be sure to consider all the factors when diagnosing the issue with your Onion. Too much nitrogen fertilizer can cause energy to be diverted to foliage growth, leaving the roots and other parts of the plant with less resources. This can be especially disappointing when harvesting a plant that looks very healthy and vigorous above the ground, since the produce it creates doesn’t match its appearance.