How to use urea in your garden in spring: 4 ways to apply fertilizer
We discuss urea, the specifics of applying it to the soil, and provide advice on proper fertilizer use in the spring.
Without proper fertilizer use, it isn’t easy to achieve a good harvest. Experienced gardeners and horticulturists know this well, which is why they use various additives to improve soil fertility. Let’s talk about the specifics of working with urea and applying fertilizer to vegetable gardens and orchards in the spring.
Be careful when using this product, follow the instructions, keep it away from children and animals, and do not store it in an easily accessible place.
All about urea and its use in spring
Features of urea use
Urea, another name for the substance, is a high-concentration nitrogen fertilizer. It contains up to 46-50% nitrogen. It is produced as small granules that are readily soluble in liquid. Solubility increases when heated. When it enters the soil, the substance decomposes. The amide form is converted to ammonia, which is then converted to nitrate. This process allows plants to obtain nitrogen in a form that is accessible to them for a long time.
Urea is guaranteed to increase yields across all crop types. Plants quickly absorb it and promote the growth of green mass. In addition, spraying fruit trees with the product in early spring delays their flowering so it does not coincide with frosts that would destroy buds and ovaries. Foliar feeding with urea is entirely safe for plants—the liquid does not burn the leaves and stems.
Despite its many beneficial properties, the product can be dangerous to plants. If the rules for applying it to the soil are violated, gaseous ammonia is formed. It can damage the root shoots. A concentration of the agrochemical in the soil mixture that is too high is also undesirable. It slows plant development and growth and reduces seed germination. The product, mainly when applied dry, acidifies the substrate, so a deoxidizer is required.
The fertilizer can only be effective if it has been stored correctly. Moisture is “contraindicated” for it. For this reason, the granules are stored only in a dry place; otherwise, they will clump and lose their properties. It is not possible to scatter the agrochemical on the substrate without subsequent incorporation. Under the influence of air, it will turn into gaseous ammonia and evaporate.
Features of urea use | ShutterStock
How to apply urea in the spring
Urea is a universal fertilizer. It can be used on all types of soil. It can be mixed with organic matter and potash fertilizers. It must not be combined with lime, dolomite, superphosphate, or chalk. Let’s take a look at how to apply fertilizer to different plants.
1. Fertilizing vegetable crops
Vegetables are fertilized by root application. Crops grown without seedlings are fertilized at planting. There are three ways to do this.
- Pre-sowing treatment. This is done during bed preparation. The granules are evenly scattered over the surface, then worked into the soil to a depth of 2.8-3.1 inches (7-8 cm) during digging.
- During sowing. The agrochemical is placed at the bottom of the furrows or holes. Be sure to cover with a layer of substrate; otherwise, seed germination will deteriorate.
- Feeding the plants. The granules are spread evenly over the beds and carefully leveled with a rake. A layer of substrate is poured on top. The bed is watered abundantly.
For vegetables grown from seedlings, a different method is used. Here is a diagram of how to apply fertilizer.
- When the hole is ready for planting, pour gallons (1 liter) of clean water into it and let it soak in thoroughly. Then pour in 0.26 gallons (1 liter) of urea dissolved in water. It is possible to add dry granules, but they must be covered with substrate to prevent the roots from contacting the product.
- The second feeding is carried out 14-18 days after the first. When the crop enters the flowering phase and forms the first ovaries, 0.26 gallons (liters) of an aqueous urea solution is applied under the bush.
The type of vegetable crop determines the solution concentration. We have presented the application rates in a table.
| Crop Application | n rate (oz/sq ft) |
|---|---|
| Radishes | 0.06–0.09 |
| Peppers | 0.07–0.08 |
| Eggplants | 0.03–0.04 |
| Tomatoes | 0.07–0.08 |
| Cucumbers | 0.02–0.03 |
| Beets | 0.06–0.08 |
| Onions | 0.06–0.08 |
| Potatoes | 0.03–0.04 |
| Cabbage | 0.07–0.07 |
| Zucchini | 0.04–0.04 |
| Garlic | 0.06–0.08 |
Foliar feeding is carried out during the growing season and when there are clear signs of nitrogen deficiency. Nitrogen deficiency manifests as slowed plant growth. The leaves become pale and small and fall off. The bush sheds its ovaries. Spraying or irrigation will help. They differ only in the method of application. In the first case, a spray bottle is used. In the second, a broom is dipped into a bucket of solution, and the green mass is irrigated.
In the case of nitrogen starvation, feeding is carried out with a high-concentration agrochemical solution. To prepare it, 0.02–0.03 oz per sq ft (7–10 g) of urea is diluted in 0.26 gallons (1 liter) of water. If the leaves are too pale, add 0.11-0.14 oz/sq ft (3-4 g) of magnesium sulfate to increase the effect. For feeding during the vegetation phase, dilute 0.11-0.13 oz per sq ft (5-6 g) of the preparation in 2.64 gallons (10 liters) of water.
2. Spraying fruit trees and shrubs with urea in spring
Berry bushes and fruit trees also need urea fertilization. In early spring, it is applied to the tree trunks. The granules are scattered evenly and then worked into the soil. This must be done carefully to avoid damaging the roots near the surface. If desired, liquid fertilizer can be applied. To do this, it is dissolved in warm water and poured around the tree trunk. We have presented the application rates in a table.
| Crop | Application rate (oz per 100 sq ft) |
|---|---|
| Pome fruits (apple, pear) | 33–49 oz |
| 65–82 oz (for bearing trees) | |
| Stone fruits (plum, cherry, apricot) | 23 oz |
| 43–46 oz (for bearing trees) | |
| Berry bushes (currant, raspberry, gooseberry) | 18–23 oz |
After spring flowering, trees are treated with urea a second time. It is best to use a foliar application method. Prepare a weak 0.5% solution of the product. Spray it on the fruit trees. Apply in calm, dry weather. The liquid is applied generously to the green mass. This can be done without fear: it does not burn the leaves.
3. Fertilizer for ornamental crops
The product is considered a spring fertilizer; applying it in the fall will be useless. In the spring, ornamental plants are fed twice. Let’s take a look at the schedule for applying urea fertilizer to flowers. It will be different for annual and perennial crops.
Annuals
- 12-15 days after transplanting seedlings or the emergence of shoots. Applied in liquid form during watering.
- 20-25 days after the first treatment for non-flowering crops and during the budding phase for flowering varieties.
The second application is best done by irrigation or spraying with a weakly concentrated urea solution.
Perennials
- In early spring, after the ground has warmed up, the product is applied dry. The granules are buried at a shallow depth. Afterwards, be sure to water generously.
- During the emergence of generative buds, irrigation or spraying with a low-concentration urea solution is used.
For ornamental and flowering crops, the application rate is 2.0–3.3 oz per 100 sq ft (6-10 g per square meter). Urea fertilization promotes the formation of bright, succulent foliage. It should be applied with caution to flowers, as excess nitrogen inhibits the budding phase.
Bulbous and root-bearing perennials such as lilies, amaryllis, irises, or calla lilies can be safely fertilized with nitrogen-containing products from the moment the sprouts appear. Tuberous varieties such as caladium or gloriosa should only be fed with nitrogen after the first leaves appear. Indoor flowers also need nitrogen fertilizers. Proportions for preparing the working solution: 0.27 oz per gallon of water (20 g of agrochemical per 10 l of water). The granules are completely dissolved by actively stirring the mixture.
Treatment rules
- Water the plants 2-3 hours before applying the fertilizer.
- It is not recommended to fertilize plants in bright sunlight and in extreme heat.
- Do not fertilize diseased or recently planted specimens.
- For plants in the shade, reduce the amount of liquid.
- Young plants and seedlings should be fed with a mixture of a lower concentration.
Fertilizer for ornamental crops | Pixabay
4. Fighting diseases and pests
Treating the garden with urea in early spring is necessary for sanitary purposes. It kills pests that have overwintered under the bark. In particular, it destroys the red apple mite, ringed silkworm, moth, copperhead, leaf roller, etc. Sanitary spraying is recommended to prevent several diseases, including powdery mildew, scab, and moniliosis.
For sanitary spraying of trees, a highly concentrated solution is prepared. If additional disease prevention is required, add 1.76 oz (50 g) of copper sulfate. The higher concentration will be safe for trees in the earliest stages, before buds open. Treatment is carried out in warm, dry weather, at temperatures above 41°F (5°C). The working concentration of the mixture is selected depending on the crop.
Recommended concentrations for different crops
- Apricot, peach, or cherry. Take 2.64 gallons (10 liters) of water and no more than 7 oz (0.2 kg) of agrochemical.
- Grapes, pears, or apple trees. Take 2.64 gallons (10 liters) of water and 1.1-1.5 pounds (0.5-0.7 kg) of the product.
The garden mixture must be prepared correctly. Here are instructions for diluting urea for spraying trees in the spring.
How to prepare the solution
- Measure out the urea granules and pour them into the bottom of a 2.64-gallon (10-liter) bucket.
- Fill it a quarter of the way with hot water. This will help the product dissolve faster. Stir vigorously.
- Measure out the vitriol and dissolve it in a small amount of hot water. Stir until completely dissolved.
- When the urea has dissolved, add the liquid vitriol. Mix well.
- All that remains is to dilute the mixture with clean water to a volume of 2.64 gallons (10 liters).
When preparing the working fluid, keep in mind that mixing causes a chemical reaction that lowers the temperature by 44.6-48.2°F (7-9°C). Treating shrubs and trees with a solution that is too cold can cause them to experience temperature shock. This must be avoided.
Fighting diseases and pests | ShutterStock
The mixture cannot be stored for long, so it should be used on the day it is prepared. Treat the plants on dry, windless days. Spray all branches and the trunk generously. The product does not have high penetrating properties. Using it before the rain is useless: it will simply wash away.
❓ Questions and answers
How should I apply urea in my garden?
You can apply urea as a dry spread, work it into the soil, or dissolve it in water for liquid feeding. It’s commonly used on vegetable beds, fruit trees, and ornamental plants.
When is the best time to fertilize with urea?
Apply in early spring before plants start heavy growth. For many crops, a second feeding later in the season can help maintain nitrogen levels.
Can urea be sprayed on leaves?
Yes — a diluted urea solution can be used for foliar feeding if plants show signs of nitrogen deficiency, but avoid spraying in hot sun.
Are there any safety tips I should know?
Always follow product directions, keep urea away from children and pets, and water it in after application to help nitrogen reach plant roots.
Hi, I’m Ben Carter!
I’m a certified organic vegetable specialist with over 12 years of experience. I grew up on a farm in Iowa and have helped hundreds of gardeners grow bountiful harvests without unnecessary chemicals. On this site, I share my proven methods. If you have any questions, leave them in the comments!
