Approximately 315 seeds per gram. Brassica oleracea Lot# BO23614 “Waltham 29” Broccoli was developed in 1950. It is a dwarf compact plant with a branching habit that grows to 45-61 cm (18-24”) high with a spread of 45-55 cm (18-20”) wide. It is a reliable heirloom that produces a solid bluish green head that is 10-20 cm (4-8”) wide. Harvest the main head while it is still tight and cut at least 15 cm (6”) of the stem. Side shoots will grow into flower heads and will continue to develop along the stem as long as the weather remains favorable. Plants are cold resistant and are able to tolerate a light frost.
Start indoors March-April or late April-May for summer harvest in 2 to 3 months. Sow indoors, 3 or 4 seeds per pot 3-5 mm (⅛-¼") deep, under very bright light and maintain a 15-21˚C (60-70˚ F) temperature. Keep soil moist but not overly wet. Thin to the strongest plant. Harden plants off for at least a week. Transplant in ground when seedlings are 5-15 cm (2-6”) tall and when they have 2 to 4 true leaves. Set seedlings 2.5-5 cm (1-2”) deeper in the garden than they were in the pots. Space transplants 45 cm (18") apart in rows 45 cm (18") apart.
Soil Conditions: Well worked rich, loose well-drained soil. Ideal pH: 6.0-7.0
Planting Depth: Sow seeds 3-5 mm (⅛-¼") deep.Space rows 45 cm (18") apart.
Germination: 7-10 days.
Height at Maturity:Broccoli reaches 76-91 cm, (30-36") tall. Spread is about is 30-40 cm (12-16") wide.
Days to Maturity: 70-90 days.
Watering: Broccoli requires a regular supply of water, at least 2.5-5 cm (1-2”) of water a week. This will ensure good growth, whether they are grown in single or wide rows. The amount of rain that falls during the week will help supplement how much you should water your garden. Soil should remain mildly moist.
Sun/Shade: Full Sun
Spacing after Thinning: Space broccoli when transplanted, to one plant every 45 cm (18”) when the seedlings are 5-15 cm (2-6”) tall with 2 to 4 true leaves.
Additional Information Continue the watering schedule to keep the soil moist during the growing season, but cut back on watering as the broccoli reaches maturity in 48 to 70 days. Harvest the main broccoli head when it’s 7.6 cm (3") in diameter to encourage more side florets. Cut the head with about 10 cm (4") of stalk. New flower heads will soon form in the leaf axils and all around the lower stalk. These will be much smaller than the initial head, but keep harvesting and they will keep producing. Water the ground under the plants and not the broccoli itself to make it less susceptible to soil-borne diseases. Allowing broccoli to produce seed will take an entire growing season, and may require digging up the plants for the winter or mulching them well. Broccoli will cross pollinate with other members of the cabbage family such as cauliflower, and isolation of at least 310 m (1/4 mile) is recommended to prevent cross breeding. Once the flowers have bloomed and produced seed pods, let them dry and carefully remove them from the plant. Separate the seeds from the pods. Store in a dry, cool place for up to five years.