Each year the United States alone produces over 70 million pounds of Brussels sprouts. These miniature cabbage-looking vegetables are a popular produce item in restaurants and grocery stores nationwide.
In the past, these small round greens had a bad reputation for being mushy and bland-many cartoons growing up featured a steaming plate of Brussel sprouts portrayed as the bane of many animated protagonists. The tables have turned, and more of us have awakened to see the value in these good veggies.
If you’ve grown tired of trekking to the supermarket to satisfy your Brussels sprout cravings, the good news is they can be grown at home. To do so successfully it will help to understand the basics behind Brussels sprout soil and fertilizer needs.
By properly maintaining the pH and nutrient levels of your garden you can ensure that come fall, you’ll have a bountiful Brussels sprout harvest.
Best Soil for Brussel Sprouts
A Brussels sprout is only as good as the soil it’s grown in. That’s why it’s important to understand both the composition and quality of your garden soil before you plant.
The majority of soil is composed of three main ingredients- sand, silt and clay. Sand particles are the biggest of the three. Soil high in sand content is well draining.
Silt is a medium sized particle formed from decayed organic matter. Silt holds moisture and nutrients well enough to give plants time to absorb the water in their soil.
Lastly, clay is the finest particle of the three. Clay is a mixture of ground up minerals which makes it extremely nutritious for plant growth. However, because clay particles are so small, they pack together very densely and can create compacted areas that prevent air or water from moving around a plant’s roots.
A good combination of the three differently sized particles creates a great texture for water and nutrient drainage and retention and also creates small gaps and crevices in your soil to allow for aeration, water movement, and root growth.
Because of this, good soil usually has equal parts sand and silt, and a little less clay (something like 40%-40%-20%). When all three of these components are mixed together the product is called “loamy soil” or just “loam”.
Brussels sprouts, and most garden plants, love loamy soil because it’s loaded with nutrients and has a great water retention to drainage ratio.
Before you plant any seeds, it’s good gardening practice to have your soil tested to make sure all key nutrients are present at acceptable levels and that the pH of the soil is in a good range.
After planting your Brussels sprouts, monitor them regularly for any signs of nutrient deficiency or waterlogging as these problems can often be fixed by re-adjusting the soil composition as needed.
Best Fertilizers for Brussel Sprouts
A good loamy soil is key to Brussels sprout growth, but even great soil can become nutrient deficient over time. In this case, a key term to know is “side-dressing”.
Side-dressing is the act of applying fertilizer or added nutrients around the base of a growing plant after the initial planting.
When growing Brussels sprouts, experts recommend tilling a complete fertilizer into the soil during the planting stage, and then side-dressing the plants with the complete fertilizer throughout the growing process as needed.
A complete fertilizer, also known as an all-purpose fertilizer, is one that contains a good dose of the macronutrients (N-P-K, nitrogen, phosphorus and potassium) and also all of the major micronutrients plants need to grow.
My favorite all-purpose fertilizers are Jack’s Classic and Organic Plant Magic. Jack’s Classic is a standard all-purpose fertilizer that is water soluble and measures 20-20-20. Organic Plant Magic is an organic fertilizer that measures 6-5-5, has a long list of different organic materials in the mix, and over 10 strains of good bacteria.
There is no rule that says you have to be completely organic or standard in your fertilizer choice. We use standard fertilizers at the beginning or end of a season, as well as compost, and typically use organic fertilizers as plants grow.
Nitrogen is a key component in photosynthesis, the process that gives plants their green color. If your Brussels sprouts don’t have access to enough nitrogen, they may turn yellow or brown or wither.
Phosphorus is responsible for growing strong roots, stems, leaves and flowers. If your Brussels sprouts are short on phosphorus you might notice severely stunted growth or less than ideal sprout size.
Lastly, potassium acts like a start and stop signal for many of the molecular processes during the Brussels sprout’s growth stage. Without potassium your Brussels sprouts won’t grow optimally and you might notice problems similar to those of a nitrogen or phosphorus deficiency.
Fertilizer can be a great addition to your Brussels sprouts if you haven’t tested your soil recently or if you’re noticing subpar growth patterns.
Follow the instructions on the fertilizer or us use 2 to 3 pounds of fertilizer for every 100 square feet of garden.
By choosing a complete, well-rounded fertilizer and using it to side-dress throughout the growing phase, you can ensure that your garden produces a substantial, healthy Brussels sprout crop.
Best Soil pH for Brussel Sprouts
The pH level of garden soil can be affected by a combination of factors. Anything from the type of minerals present in the soil to the amount of rainfall the garden receives can raise or lower the pH beyond ideal limits.
On a scale from 1 to 14, soils with a pH value over 7.5 are considered alkaline while a pH value lower than 6.5 indicates acidic soil. A value between 6.5 and 7.5 is considered neutral.
When it comes to Brussels sprouts, experts say the plants prefer a neutral or slightly acidic soil pH of 6-7.
The pH level of the soil is largely responsible for determining how well the plant can uptake nutrients. If the soil pH rises too high, the Brussels sprouts won’t receive enough iron and magnesium. This can cause the leaves to become yellow and shriveled.
On the other hand, if the pH level becomes too acidic, this can also cause poor nutrient uptake and encourage fungal growth and the development of “clubroot”. Clubroot causes the roots of the plant to become swollen and the plant’s growth is heavily stunted.
If the soil pH in your garden is too high or low for your Brussels sprout crop there are a few additives that can be mixed into the soil to adjust the pH accordingly.
For alkaline soil, sulfur or nitrogen fertilizer can make the substrate more acidic. Likewise, if the soil is too basic, mineral compounds such as calcitic lime or dolomite can be mixed in to raise the pH.
If this is your first time gardening or if it’s been a while since you last had your soil tested, it’s a good idea to pick up a soil pH test or soil test kit.
Knowing the pH and nutrient content of your soil can save you headaches later and help in your quest to grow the healthiest Brussels sprouts possible.
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