The best fertilizer for root vegetables is either a balanced fertilizer such as 10-10-10 fertilizer or a fertilizer with slightly lower nitrogen content, such as 5-10-10. These are common types of fertilizer that can be found in most home and garden stores. As an added boost, it’s a good idea to work compost into the soil to encourage healthy root crops. However, compost typically contains fewer nutrients than fertilizer, so you cannot fully replace fertilizer by using compost.
Do Root Vegetables Need Fertilizer?
Root vegetables are like all garden plants—they need fertilizer. If you do not fertilize your root crops, the plants may fail to thrive or may even die. This is because poorly fertilized root vegetables are more susceptible to insect destruction and disease. If your root crops do survive without fertilizer, you will get a small harvest with stunted roots. So, fertilizing your root veggies is essential to get a bountiful harvest.
What is the Best Fertilizer for Root Vegetables?
10-10-10 fertilizer is great for growing most common root vegetables. This balanced fertilizer works great for radishes, carrots, and beets. Plus, 10-10-10 is so versatile that it can be used to fertilize most above-ground vegetable varieties, including tomatoes, peppers, and squash. With 10-10-10 fertilizer, you can fertilize your root vegetables with the same product you use for the rest of your garden. This saves you time and money.
- Use this 10-10-10 fertilizer for carrots, radishes, and beets.
- If you’re growing potatoes, turnips, or yams, use this 5-10-10 fertilizer.
- Starchy root vegetables—such as potatoes—thrive on the extra phosphorus and potassium found in 5-10-10 fertilizers.
If you are growing starchy root vegetables, use 10-20-20 fertilizer or 5-10-10 fertilizer. In fact, one of the best uses for 10-20-20 fertilizer is for growing potatoes, turnips, and sweet potatoes. The additional potassium and phosphorus in 10-20-20 helps these large, dense, starchy roots develop properly. So, you’ll get bigger tubers for delicious baked potatoes.
How Do You Fertilize Root Vegetables? [3-Step Method]
In order to grow the healthiest root vegetables, it’s essential to fertilize your soil in 3 stages. Here’s the method that will ensure you grow healthy plants on your first try:
Prepare the Soil with Compost
Before you plant your root crops, prepare your garden soil with organic fertilizers. Spread 2–4 inches (5–10 cm) of this organic compost on top of the soil in your garden bed. Then, use a shovel, rake, or tiller to mix the compost into the top 12 inches (30 cm) of soil. This will loosen the soil to allow root crops to grow properly, while at the same time introducing natural fertilizers into the soil. However, compost isn’t enough to grow thriving root vegetables on its own.
Fertilize Right After Planting
Immediately after planting, evenly spread 1.5 pounds of 10-10-10 fertilizer per 100 square feet of your root garden. This is ideal for carrots, radishes, and beets. If you are growing starchy root veggies (potatoes, yams, or turnips) use 1.5 pounds of 5-10-10 fertilizer for every 100 square feet of garden soil. Water the soil after spreading the fertilizer. Then, continue watering normally as your plants sprout.
Fertilize Once Monthly
After planting, continue to fertilize your root vegetables once every 4 weeks. Repeat the same application rates you used right after planting. Use the same fertilizer type you used at planting. Water the fertilizer into the ground. Continue this fertilizer schedule as the plants develop. Then, stop fertilizing 2 weeks before you harvest your veggies.
How Often Do You Fertilize Root Vegetables?
It is best to fertilize root vegetables once every 4 weeks. This is especially important for slow-growing root crops, such as potatoes and carrots. A consistent fertilizer schedule encourages root growth and prevents disease and rot from ruining the crop underground. Fast-growing root crops—like radishes—have slightly different rules. So, it’s best to check out our detailed guide for growing radishes.
Is Fish Fertilizer Good for Root Vegetables?
Fish-based fertilizers are not a good choice for growing root vegetables. Fish meal has a nutrient ratio of 6-10-2, which means it is low in potassium (the 2 signifies the potassium content). Potassium is essential for root vegetables to develop healthy, flavorful roots. If you use fish meal, your vegetables may develop stunted, poor-quality roots. It’s better to use 10-10-10 or 5-10-10 fertilizer for your root garden.
What Fertilizer Should You Use for Carrots and Beets?
A balanced fertilizer—such as 10-10-10—is the best option for carrots and beets. This fertilizer is “balanced” because the 3 numbers on the fertilizer means it contains equal parts nitrogen, phosphorus, and potassium. These 3 nutrients will contribute to healthy roots and foliage for your beets and carrots.
Should You Put Manure on Carrots?
You should never put uncomposted manure on carrots or any other plant. Manure is terrible fertilizer and contains harmful bacteria that can infect your soil and make your carrots dangerous to eat. If you wish to use manure to fertilize carrots, make sure to use fully composted manure. The composting process will kill off bacteria, resulting in a safe fertilizer. Source your compost from a reputable vendor, so you know it’s safe for use on vegetables.
What Fertilizer Makes Roots Grow?
Phosphorus is the nutrient most associated with root growth. For most plants and grasses, phosphorus is essential for root development, especially during the early stages of the plant’s life. However, root vegetables operate differently than grasses, trees, and flowers. In the case of root vegetables, the root is also the fruit. So, specialized plants like carrots and potatoes also need nitrogen and potassium to develop healthy, flavorful roots.
What Do You Add to Soil for Root Vegetables?
When growing root vegetables, follow these fertilizer rules:
- Use 10-10-10 fertilizer for carrots, radishes, beets, and parsnips.
- 5-10-10 is the best fertilizer for potatoes, sweet potatoes, and turnips.
- Before planting your root vegetables, mix compost into the top 12 inches (30 cm) of soil.
- Immediately fertilize with 10-10-10 or 5-10-10 fertilizer after planting.
- Continue fertilizing your root vegetables once every 4 weeks.
- Stop fertilizing root vegetables 2 weeks before harvest.
These quick rules will enable you to grow delicious, edible roots in your garden. Now, you can add carrots and potatoes to your harvest, alongside your other homegrown fruits and veggies.