Brussels Sprouts

General Information:
Brussels sprouts are a really interesting vegetable to grow. The heads grow on the main stem and can be eaten anytime mature enough to harvest. Brussels sprouts are one of the hardiest plant in the garden. They will actually taste better if subjected to frost and light snow. For this reason gardeners in the north have an advantage over us southern gardeners. For this reason I only grow Brussels sprouts in the fall. Brussels sprouts will grow to 2' to 3' tall with adequate cultural practices. Brussels sprout are shallow rooted and require above average nitrogen and significant boron content for a great harvest very similar to cabbage and broccoli. Soil Ph is also of great importance for this vegetable. The "sprouts" (small heads that resemble miniature cabbages) are produced in the leaf axils, starting at the base of the stem and working upward. Brussels sprouts require a long growing period, though newer hybrids have greatly reduced this requirement. In all but the most northern states, summers are usually too warm for completely satisfactory production from spring plantings. Plants set out in late spring to early summer grow satisfactorily and mature high-quality sprouts when the fall weather begins to cool.

Soil Preparation:
For best results incorporate moderate amounts of compost or well rotted manure deeply dug into the soil. Beware of fresh manure as it may contain seeds, & high concentrations of urine & salts. Using a garden hoe form a shallow trench in the center of the 36" wide bed about 4" deep. Do not allow the trench between the 2 rows too extend beyond the end of the beds as this trench will hold water later.  The 2 rows in the 36" wide bed should be about 12" apart. Since Brussels sprouts are a shallow rooted plant it is very sensitive to moisture fluctuations.   Without adequate moisture the shallow roots  cannot deliver the required nutrients to produce properly.  Rake to break up & remove debris from the soil. Work the soil only when it is dry enough not to stick to garden tools.  Soils that are well-suited for the production of Brussels sprouts are fertile, well drained, and have texture ranging from sandy loam to clay loam.

Seed starting:
A great Brussels sprouts crop begins with large vigorous health seedlings 4 to 6 weeks old, grown in 4" or larger growing pots. Growing your own seedlings insure quality and varieties not commercially available. Brussels sprouts seedling are commonly found commercially if you prefer just buying your seedlings. The seeds should be started about 4 to 6 weeks before your average last frost date in your zone, or 4 to 6 weeks before your last frost date for a early spring crop.  Make sure the seed starting mix is a light sterile soil mix with a liberal portion of Perlite or Vermiculite to maintain moisture.  Sow 2 seeds per 4"pot about ¼" deep in pre-moistened growing mix. Fill the growing pot to within 1" of the top of the pot. Add and additional ½" of soil as they mature for better root formation. During the day, keep the seedling  next to a sunny window after they have germinated. Move to top of the water heater or refrigerator at night if you do not have a greenhouse. A heated greenhouse will produce ideal, controllable growing conditions. I also use supplemental overhead florescent lighting when needed.  Never allow your lights to burn more than 16 hours per day. A cheap electrical timer is the key to success here. Seedlings must be allowed to have a period of rest from light to grow properly. Hang your lights 1½ inches above the tops of the seedlings. This will prevent the seedling from becoming leggy. Raise the lights suspended by a chain as the plants grow. Do not allow the soil to dry out.  I feed my newly emerged seedling every other watering cycle. I prefer feeding my young seedlings with Fish Emulsion or liquid seaweed.  After they have grown 2 true leaves I use a fertilizer high in phosphorus like Scotts Peters Professional 9-45-15 plant starter item #91140. Call 1-800-492-8255 for a dealer near you. Fertilize every two weeks until transplant time. Four weeks after seedlings have emerged clip off at the soil line the smallest of the 2 seedlings with scissors.

Fertilization:
Perform a complete soil analysis to determine fertilization needs.  Soil sample kits including sample bag and instructions can be  obtained from your local county  Agricultural extension service office free of charge. However the fee  for the actual soil analysis is usually about $15.00.   

Generally apply  about ½ cup of ammonium nitrate  fertilizer for each 10 feet of 36" wide bed. This should be applied and worked into the soil  3" deep about one week before the plants are set. Brussels sprouts  plants are shallow rooted heavy feeders requiring ample, even supplies nutrients including  Nitrogen, Phosphorus, Potash, & Boron.  It is always wise to follow a nitrogen fixing crop such as  beans , hairy vetch, rye or buck wheat if possible. Time released fertilizers like Osmocote have become very popular and work great lasting  for 4 months. An organic fertilizer such as fish emulsion can be used bi-weekly.

Hardening Off:
It will be necessary to harden off your seedlings before transplanting into the garden bed. The seedling must become accustomed to the harsher elements outdoors. This is accomplished by placing the seedling outside to a sheltered location. At this point the seedlings are very tender and easily broken by wind and rain. Start out by placing the seedling in full morning sunlight for one hour. Increase the time in full sunlight gradually adding time each day. Protect your seedlings from wind and animals to prevent breakage of the tender vegetation. Within two weeks your plants should be able to stand full sunlight the entire day without wilting or burning the tender leaves. At this point your seedlings are ready for the harsh elements of the garden.

Planting & Growing:
Transplant 2 rows of seedlings  spaced about 12" to 18"  apart in the center of the rows formed earlier.  Plants can be set slightly deeper  when transplanting. Water the seedlings well  in growing pot 1 hour before transplanting.  Water the plants well during transplanting  using about 1 pint of starter solution on each transplant, or use commercially prepared starter solution according to manufacturer's instructions.  This can be a weak solution of  20-20-20  general plant food or commercially available root stimulator. This will encourage rapid root growth & produce sprouts of acceptable quality.   To lengthen the harvest plant seedling plant 1/3  at a time 1 weeks apart.  This procedure will also require starting your seedlings 1 week apart as well.  Cover the entire  36" wide bed including the trench between the rows with leaves or straw mulch. The mulch will retain moisture, attract worms, and reduce the growth of weeds in the beds. Any weeds that do germinate are easily removed by hand or light cultivation.    When it is time to water your plants simply apply a moderate amount of water into the trench between the row you formed earlier.  Do not apply water to quickly as you may wash out  soil holding the water. The water will slowly soak deeply onto the root zone.  Using this method your plants will always have adequate moisture to perform well.  Be prepared to irrigate 1 to 1 1/2 inches of water per  week if natural rainfall is lacking to help ensure a high-quality crop. Brussels sprouts requires above average moisture, and when this is lacking it responds with slow growth and poor appearance. Excessive rainfall will present a problem as Brussels sprouts don't like to stand in water for prolonged periods causing root rot.

Direct Seeding:
Seeds can also be started by directly sowing into your prepared wide row beds. I do not recommend direct seeding into the garden. Starting seedling in pots affords better control of the elements when seedling are young and tender. Plant 2 seed ¼" deep about 4" apart and water gently. Four weeks after seedling have emerged thin the seedlings to 16".  Clip the smallest one at ground level with scissors.   Brussels sprouts are sometime difficult to germinate when direct seeding .   Monitor insects closely during this time.

Harvesting:
Brussels sprouts should be harvested in the early morning  assuring peek flavor. The mature head should be cut as needed  to prevent spoilage. The small sprouts or buds form heads one to two inches in diameter. They may be picked (or cut) off the stem when they are firm and about one inch in size. The lower sprouts mature first.

Yield:
Sprouts will vary in size, depending on variety, spacing and growing conditions.

Storage:
The fresher the sprouts, the better the flavor, so refrigerator storage should not exceed a day or two. Remove any damaged or irregular outer leaves and store fresh in a plastic bags in the vegetable bin of the refrigerator.