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Brussels sprouts (Brassica oleracea var. gemmifera), kale, broccoli, cauliflower, and kohlrabi, are all hybrids of the wild cabbage (Brassica oleracea). As the name indicates, it was developed in the capital of Belgium, Brussels. It is classified as “moderately difficult” to grow.
10 Surprising Tips to Make Your Brussels Sprouts Flourish
This piece is for those who know the basics of growing Brussels Sprouts. If you’re unsure, check out my article on the topic.
So, let’s dive deeper and cover some finer skills of growing Brussels sprouts (and other plants).
Tip #1 – Let Other Plants Prepare Your Brussels Sprouts Beds
As we’ll see below, crop rotation has several functions. This suggested multi-year cycle allows you to use a single bed for ten crops in four years without compromising plant health.
Some of these crops are cover crops, something I cover in my second tip. The sequence allows you to use the characteristics of the preceding plants to provide growth and health assets to the subsequent crops.
Plant six vegetable crops in four years, interspaced with four cover crops.
- Prepare your bed for next year’s crops in the Fall: Plant oilseed radish as a cover crop.
- April-June: Plant a non-brassica leafy green (endives or lettuce) in the same bed
- July-August: Grow a grain crop – sweet corn matures in 2 months if the soil is warm enough (65°F/18.3°C). Some hybrids will let you get away with 55°F/12.8°C.
- August-November: Grow a fall season Brassica like Brussels sprouts
- November-June: Cereal Rye cover
- June-October: Plant a Solanaceae crop – pepper or eggplant
- October-May Hairy vetch/Cereal rye mix
- May-September: Grow onions or other Liliaceae crop
- September-November: Oats and field peas cover crops
- May-September: Grow Cucumber
- September-November: Return to point 1
Tip #2 – Precede Brussels Sprouts With the Right Cover Crops
In the cycles above, we used the following:
Oilseed Radish
Oilseed radish is a quick-growing ground cover crop that smothers weeds and protects against soil erosion. Its taproot is substantial and helps break up compacted soil layers.
The allelopathic characteristics of oilseed radish help control soil-borne pests, including insects, weeds and nematodes.
These characteristics may prevent seed germination, so we leave a gap before we follow it up with a crop we’ll grow from seedlings (not in situ seeds).
Grain Crops
Our grain crop that precedes the Brussels sprouts further helps manage nematodes that may impact our Brussels sprouts (or other brassica fall crops).
5 Benefits of Cover Crops
- Soil texture. Microorganisms secrete a glue-like substance that binds soil particles together to form stable aggregates, improving the soil’s ability to absorb water without compromising soil oxygen levels (saturation porosity).
- Soil fertility. The humus level of your soil will increase as organisms break down the dead cover crops into nutrients that crop roots absorb.
- Weed, disease, and insect protection. Organisms will break down dead cover crops into bioavailable nutrients. Increased biodiversity improves plant resilience.
- Moisture. Cover crops increase soil organic matter, improving cation exchange capacity (CEC) and creating a habitat for beneficial microorganisms.
- Erosion prevention. The dense foliage of the cover crop shields the soil from wind and heavy rain, while the plants’ roots help to keep the soil in place.
Tip 3 – Heat Treat Brussels Sprouts Seeds
Most disease-causing organisms on or within seeds can be killed by treating them with hot water. Seeds of cruciferous vegetables, including Brussels sprouts, benefit from this treatment.
To eliminate disease-causing organisms on your seeds without chemicals, try heat-treating them first. Seeds may harbor bacteria that can be eliminated early.
Thermostatically controlled water baths are ideal for the precise timing and temperature control required for seed heat treatment. If you don’t have one, ensure the water temperature is stable before inserting the seeds.
Make a pouch from an untreated cotton material to place the Brussels sprout seeds. Make sure not to overfill the little sachet. The seeds need to be able to move about freely if the hot water is to reach all of them.
The first cycle is a 10-minute pre-heat at 100°F/37°C. Then the Brussel Sprouts seeds need to be immersed in water that is 122°F50°C for 25 minutes.
As soon as the time is up, remove the sachet of seeds and rinse them in dechlorinated cold water to stop the heating. Carefully remove the seeds from the pouch and allow them to dry.
All treated seeds should be used soon after treatment. You can dust the seed with Thiram 75WP as an additional safeguard.
Tip 4 – Lob to the Top for Bigger Brussels Sprouts
The shoot apical meristem (SAM) is where cells reproduce and cause the growth of the stem, branches, and flowers. The meristem is just above the ground for grasses, and for dicots, the growth point is at the apex.
Cutting the apical stem growth point off causes the Brussel Sprout to channel available resources to maturing the little sprouts.
Tip 5 – A Frosty Kiss Adds Sweetness
Improve the taste of your Brussels sprouts by planting them in time to allow them to reach maturity after your first frost date.
The Brussels sprout plant stores excess nutrients as starch (as do turnips). Frosty temperatures cause these scratches to convert to sugars, making the plant taste better.
Tip 6 – Boost the Microorganism Population
The best thing you can do for your garden and the planet is to produce and use compost. Compost hosts billions upon billions of microorganisms essential for plant resilience and productivity.
Add 4 inches (10 cm) of compost to your raised bed for improved CEC and drainage. The compost microorganisms attract another soil biota (macrofauna) that feed on harmful fungi and bacteria.
Tip 7 – Put your Brussels Sprouts on a Drip
Avoid wetting the leaves of Brussels sprouts. The same applies to fruiting vegetables, cucurbits, and other brassica plants.
Wet leaves help pathogens spread, causing the spread of diseases. If your Brussel sprouts leaves are wet from rain, avoid working in the garden until the leaves have dried.
Tip 8 – Get the Brussels Sprouts Diet Right
Like other leafy greens, Brussel Sprouts need the energy to grow – the energy they get from nitrogen. It’s fine between boosting foliage growth and health and forcing sprout development.
Initially, you want to optimize photosynthesis, so leaf health is essential, but as sprouts mature, you may want to up potassium, which is responsible for fruit development.
Monitor Boron levels, as its absence will limit your Brussels sprout’s productivity.
Tip 9 – Stop Brussel Sprouts from Bolting
Brussel sprouts are biennial plants, growing foliage in year one and seeds in year two. Warmer temperatures trigger seed production, so the Brussels sprout needs to keep cool.
While Brussels sprouts love full sunshine, they can handle some shade which you should provide them if things start warming up.
Tip 10 – Harvest and Store for Christmas
If you harvest the Brussels sprout stalk with the sprouts attached, you can hang it up in a cool dark place for later consumption.
Brussels sprouts handle temperatures of up to 25°F/-4°C quite well, so save some for Christmas.
In Closing
There are ten surprising tips to make your Brussels sprouts grow like crazy! Follow them and make this fall crop boom.
