Repotting your houseplants is important to allow them room to grow. But while it is necessary, plants need time to adjust to their new soil and environment after repotting, or they will go into transplant shock.
You can put fertilizer in after repotting but you don’t need to. Most varieties of potting soil already contain some amount of fertilizer. If you’re making your potting mix, you should only add organic or slow-release fertilizers to prevent burning any new roots that grow after repotting.
In this article, I’ll explore when you should fertilize plants after repotting and how you can do this effectively. I will also explain how you can identify the right kind of fertilizer for your plants, how to apply, and when to apply it.
When to Fertilize Plants After Transplanting?
Transplanting or repotting is necessary for potted plants and sometimes even for farm crops. Since it allows the plant more room to grow. However, new roots are fragile and easily overwhelmed by water or fertilizers.
You should fertilize plants about 4 to 6 weeks after transplanting. This gives the plant time to grow new roots and strengthen them. Newly grown roots are fragile and can be burned easily by fertilizers. So, it is important to give your plant time to adjust before fertilizing it to help it grow.
When plants get transplanted, they may go into transplant shock, a time when root growth stagnates because of the changes in the environment. Transplant shock is more likely to occur if you had to prune the roots for any reason. Any further changes like adding water or fertilizer at this point will only shock the plants further.
With time, plants go into recovery mode once they regrow their roots. However, the new roots will be thin, fragile, and susceptible to drowning in too much water or burning due to fertilizer.
While you can water your plants about a week after repotting, you should wait about a month before adding any fertilizers to your pot. You can also choose to water and fertilize your plants before repotting to encourage new growth and support the plants as they adjust to their new surroundings.
If you really must add fertilizer to your plant, it is best to incorporate organic fertilizers like compost and potting soil as these release their nutrients slowly. You can also mix inorganic fertilizers with the soil as long as they are slow-release.
An important thing to note is that most commercially available potting soil contains fertilizer. As such, you can go up to 8 weeks without adding any additional fertilizer.
While you can feed a weak plant, fixing fertilizer burn on a plant can take much longer and require a lot of effort.
Fertilizing Your Potted Plants to Improve Their Health
Fertilizing your plants is a way to improve overall plant health along with eliminating pesticides.
Fertilizers add nutrients to the soil that help plants grow bigger and faster. They also help improve overall longevity and resistance to pests and diseases. 3
The main nutrients needed by plants are called macronutrients, and these are:
- Nitrogen
- Phosphorus
- Potassium
Each nutrient performs a different function for the plants and needs to be supplied in the correct proportions to ensure that your plants grow optimally.
Before you add any fertilizers to your plants, you need to get a soil analysis performed on your chosen potted soil. This is to check which nutrients are necessary and identify the pH of the soil. The soil analysis will help you determine what kind of fertilizers to use to help your plants thrive.
When adding fertilizer to your plants, you need to consider the type, how to apply it, and when to apply it to benefit your plants.
Often, we repot plants during the growing season, which is also when they should be fertilized. However, it is important to time your fertilizer application correctly to benefit plants like tomatoes to avoid creating issues like fertilizer burn.
The Best Type of Fertilizers to Use After Repotting
After you’ve analyzed the soil and considered the needs of your potted plants, you’ll have a fair idea about the nutrients needed in your fertilizer.
After repotting, plants mostly draw nutrients from the new soil or the fertilizer incorporated in it, which should last the plant a while. Therefore, you can wait for anything between 4 weeks to 6 weeks before you start fertilizing again.
It is important to start with a weak fertilizer to keep your plant roots from getting burnt. Using a diluted inorganic or organic liquid fertilizer is a good way to distribute the nutrients evenly.
You can also use slow-release fertilizers like compost or fertilizer sticks, as these will last your plants a long time.
Slow-release fertilizers are helpful, as plants that have been repotted tend to need more fertilizers than other plants. Repotted plants have room to grow, so they will start actively consuming nutrients and growing new roots and leaves.
During this period, slow-release fertilizers are ideal, as they ensure sustainable, consistent growth in your plants. If you’re using other fertilizers, you may have to apply them lightly and more frequently to support the plants as they grow.
Additionally, using fertilizers that are heavier on phosphorus is recommended for newly repotted plants as phosphorus contributes to root growth and leaf growth.
Applying Fertilizer Correctly
Whether you’re using solid or liquid fertilizers, there are several different ways of applying fertilizers to your potted plants.
Solid fertilizers can be applied in the following ways:
- Broadcasting: Spreading the fertilizer around the base of the plants.
- Placement: Adding small quantities of fertilizer into the soil, either deep in the soil layers or near the plant. Both granules and fertilizer spikes can be used in this way.
- Pellet Application: Pellets mixed in a ratio of 1:10 to soil and deposited in the soil.
Liquid fertilizers can be applied in the following ways:
- Starter solutions: Starter solutions are typically used for young plants and seedlings when they’re being repotted and help young plants grow quickly.
- Foliar applications: Foliar applications refer to fertilizers that are absorbed from the leaves of the plant. For repotted plants, the solution must be very dilute, to begin with, even if you’re using organic fertilizers.
- Application through irrigation water: Water-soluble fertilizers are added to the water used to irrigate the plants.
- Soil injection: Fertilizers are injected into the soil, either on the surface or under the top layer.
Regardless of whether you’re using solid or liquid fertilizers, it is important to apply them correctly. This ensures that your newly repotted plants are able to absorb the nutrients and grow quickly.
It is important to start small by controlling the volume and concentration of your fertilizers. Even slow-release fertilizers can burn your plants if you use too much of them at once.
Finally, avoid concentrating your fertilizers in one spot. Distribute the fertilizer as evenly as you can to ensure that your plants grow evenly and are not shocked by excess fertilizer in any one area.
Timing Your Fertilizer Application
The best time to fertilize your houseplants is when they’re actively growing, which is usually in spring. This may vary depending on the origins of your plant, so make sure you know your plant’s specific needs.
Plants that have outgrown their pots usually need to be repotted during the growing season as well to ensure they have room to grow bigger.
If you are expecting a long spring and summer and your plant isn’t root bound, you can apply diluted fertilizer to your plants about a week before you repot them. This will help the plant store up nutrition before repotting. Malnourished plants are more likely to experience transplant shock.
Make sure to water your plants about an hour before they get repotted.
Once you repot your plants, wait for anything between 4 to 8 weeks before reapplying fertilizer. The ideal amount of time is six weeks, but if your potting soil doesn’t contain any fertilizer, you can start at four weeks.
Use diluted fertilizer, but fertilizer your plant every two weeks to support growth at this time.
If you’re using slow-release or starter fertilizer, you should add those in with the potting soil. These fertilizers are meant to support your plant through the transplantation process and will not burn your plants unless you use too much of them.
It is advisable to water your plants before you fertilize them. The water helps them absorb the fertilizers without the desiccation that leads to burning.
Final Thoughts
You can add fertilizer after repotting if you’re using a slow-release, organic, or starter fertilizer. If you’re not using slow-release fertilizers, you should wait about 4-6 weeks to add fertilizer to your plant to give it the chance to grow and strengthen its roots.
If you fertilize too early, you risk burning the new tender roots with the fertilizer. Most potting soil contains fertilizer as well, so you can even go as long as eight weeks without adding any to your repotted plants.
