Skip to Content

The Best Way To Fertilize Young Cucumber Plants – How To Get Your Plants Growing!

What is the best way to fertilize young cucumber plants to get them growing strong early? And, how can you make sure to keep powering them just right to grow and produce a big crop of cucumbers all summer long?

That question is certainly a popular one each and every spring as gardeners begin to plant their cucumber plants or seeds into the ground. Cucumbers can flourish in a traditional garden setting, raised beds or even in pots and containers. Especially when they are given the proper nutrients they need to thrive.

When it comes to growing healthy and productive cucumber plants, both how and when you fertilize can make a huge difference in both the longevity of the plant, and just how many cucumbers you will be able to harvest from it.

harvesting from the garden
Giving your cucumbers the nutrients they need when they need them is one of the biggest keys of all for growing success.

No matter where or how you grow cucumbers, they need a steady supply of nutrients to develop. Not just for later when they begin to flower and fruit, but when they first begin to grow. Without a strong system of roots or a healthy canopy of foliage, cucumbers can’t produce a strong bloom set. And without flowers, there simply can’t be cucumbers!

That is exactly why fertilizing your cucumber plants early and as they develop and mature is important. In fact, the ability to provide them with a consistent supply of energy is really the single biggest key of all to cucumber growing success.

The Best Way To Fertilize Cucumber Plants

There are three critical times to supply cucumber plants with power. The first is at planting time. The second is during the first six to eight weeks of their life in the soil. The third and final time is as they begin to fruit.

But even though they need energy at all three of these points, the nutrients they need differ. And by simply providing them with exactly what they need when they need it, you call but ensure a big harvest. With that in mind, here is a look at each fertilizing stage, and how to power your cucumber plants for maximum production and health.

Fertilizing At Planting Time – The Best Way To Fertilize Cucumber Plants

Success with growing cucumbers all starts with getting them off to a great start on planting day. The best way to do that is to give them all kinds of great nutrition in their planting hole – whether your planting seeds or transplants.

Listen Below To Our Podcast On How To Grow Amazing Cucumbers!

When it comes to supplying energy to the planting area, nothing can beat compost. If you are planting seeds, always mix in generous amounts of compost to the soil. How much compost? A good rule of thumb is to create your planting hole or mound with a 50/50 mix of soil and compost.

Compost truly is the perfect, all-natural, fully-balanced, slow release fertilizer. Not only is it loaded with nutrients, it also contains all kinds of beneficial organisms. Most importantly, compost helps to retain moisture in the soil. Moisture that is vital to helps seeds germinate and grow quickly.

Fertilizing Transplants – The Best Way To Fertilize Cucumber Plants

If you are planting cucumber transplants, once again compost is the answer. Begin by digging your planting holes to three to four times the size of your root ball. Fill the hole with a 50/50 mix of soil and compost, setting the transplant in so that the top edge of transplant soil is slightly higher than the surrounding soil.

This will help the plant drain away excess water and prevent rot. Cucumbers need water and moisture to thrive, but they are highly susceptible to root rot. Especially right at the main stem. Sitting the plant up a bit will help eliminate this issue.

One thing you do not want to mix into your planting hole when planting is a high potency fertilizer. Compost is the best choice, as it will provide a slow trickle of nutrients. Too much power at planting time can produce too much foliage growth, or even injure the plant.

best way to fertilize cucumbers - compost
Applying a layer of compost around your plants will provide lasting, slow-release power.

Mulching With Power – How To Fertilize Young Cucumber Plants

Once your transplants or seeds are in the ground, it’s time to mulch. Mulch not only helps to keep weeds under control, but also helps regulate soil temperature. Both are two big keys for growing healthy, productive plants.

But when you mulch your cucumber plants, you can also give it more low and slow power with two simple ingredients – more compost and worm castings.

Start by applying a one to two inch thick layer of compost approximately six inches in diameter around each plant or over the top of each seed hill. Into each hill or plant area, also mix in a quarter cup of worm castings to the compost as well.

Why the worm castings? Worm castings provide a slow, balanced supply of nutrients that are easily absorbed by the plant’s roots. And will they ever get your young transplants off to an incredible start. This is probably the one step gardeners skip most – and yet, it so important for young plants!

how to use worm castings
Worm castings are filled with a balanced blend of nutrients that are incredible for powering young cucumber plants.

The “ring” of compost and castings will act as the ultimate slow release fertilizer every time you water or it rains. Nutrients will slowly leach into the soil below, giving the plants instant but balanced power to grow.

If you are planting transplants, after putting down the compost, apply a regular layer of mulch ( straw, shredded leaves, etc.) on top of the compost and castings. If planting seeds, wait until the seeds sprout before adding the additional mulch on top.

Fertilizing Cucumber Plants As They Grow – The Best Way To Fertilize Cucumber Plants As They Grow

Once your plants are in the ground and established, the next step is to begin providing them with regular, but light applications of fertilizer as they develop. It is important to note those two key words, regular and light, make a huge difference in how to fertilize for success.

Provide your plants with no additional fertilizer after planting and they will likely under perform. But give them too much, and they will spend all of that excess energy producing stems and foliage, and little to no blooms or cucumbers.

liquid fertilizer
Liquid fertilizers are the way to go when fertilizing cucumber plants.

This is exactly why a regular but light application of fertilizer will work best. It gives plants a steady dose to keep them healthy and strong, but not so much that they overgrow foliage. It is a delicate balance for sure, but there is an easy way to give your plants what they need.

How To Fertilize Young Plants – How To Fertilize Cucumber Plants

For best results, once your cucumber plants have established, fertilize with a light dose of liquid organic fertilizer every two weeks for the first eight weeks. It is important to allow them to establish in the soil before fertilizing.

Establishing means giving the plants 7 to 10 days to adjust their roots into the soil. For seeds, it means allowing them to grow enough that the seedlings are at least a few inches high and have developed 3 to 5 leaves.

As for fertilizer, liquid is a better choice than granular. Liquid fertilizers work in two ways. Their nutrients are absorbed by the leaves of the plants and also through the roots. This double action allows plants to get more energy at a much better rate than by using granular fertilizers.

As for the light dose, simply cut back on the strength of the fertilizer by diluting it. If using a commercial fertilizer mix, make it half the recommended strength. If using compost tea or worm casting tea, you can use them at full strength as the nutrients are more gentle and not as potent. See: Compost Tea Recipe

Fertilizing As Plants Mature – How To Fertilize Cucumber Plants

Finally, once plants begin to fully produce, you can back off on fertilizing. At this stage, a light dose every three weeks will do the trick, keeping plants stocked with energy, but not allowing them to have so much they will stop producing new blooms. What is important at this stage is harvesting!

Harvesting regularly is equally important to fertilizing your plants for overall production levels. Cucumber plants, like many vegetable plants, can suffer from what is known as fruit overload. Fruit overload is a fancy term that simply means there are too many ripe cucumbers on the vines.

When this occurs, it is a signal to plants to stop producing new blooms so they can concentrate on ripening fruit. So keep picking those cucumbers and watch the harvest totals grow. Here is to fertilizing your cucumber crop this year from start to finish – and to a huge harvest too!

This Is My Garden is a garden website created by gardeners, for gardeners. We publish two articles every week, 52 weeks a year. Sign up today to follow via email, or follow along on Facebook here : This Is My Garden. This article may contain affiliate links.