Waltham 29 Broccoli
Brassica oleracea var. italica 'Waltham 29'
Developed at the University of Massachusetts, this cold-hardy broccoli variety was specifically bred to extend the growing season well into winter in northern climates. It produces medium-sized, deep blue-green heads followed by an abundance of tender side shoots that can be harvested for weeks. This reliable performer is perfect for gardeners wanting fresh broccoli through the fall and early winter months.
Harvest
65-74d
Days to harvest
Sun
Full sun to partial shade
Zones
6–9
USDA hardiness
Height
10-24 inches
Planting Timeline
Showing dates for Waltham 29 Broccoli in USDA Zone 7
All Zone 7 brassica →Zone Map
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Waltham 29 Broccoli · Zones 6–9
Growing Details
Zone-by-Zone Planting Calendar
| Zone | Indoor Start | Transplant | Direct Sow | Harvest |
|---|---|---|---|---|
| Zone 3 | March – April | May – June | May – June | July – October |
| Zone 4 | March – April | May – June | April – June | July – October |
| Zone 5 | February – March | April – May | April – May | June – November |
| Zone 6 | February – March | April – May | April – May | June – November |
| Zone 7 | February – March | April – May | March – May | May – November |
| Zone 8 | January – February | March – April | March – April | May – December |
| Zone 9 | January – January | February – March | February – March | April – December |
| Zone 10 | January – January | February – March | January – March | March – December |
Complete Growing Guide
Light: Full sun (6 or more hours of direct sunlight a day), Partial Shade (Direct sunlight only part of the day, 2-6 hours). Soil: Clay, Loam (Silt), Sand. Soil pH: Acid (<6.0), Neutral (6.0-8.0). Drainage: Good Drainage, Moist. Height: 0 ft. 10 in. - 2 ft. 0 in.. Spread: 1 ft. 0 in. - 2 ft. 0 in.. Spacing: 12 inches-3 feet. Growth rate: Medium. Maintenance: Medium. Propagation: Seed, Stem Cutting. Regions: Coastal, Mountains, Piedmont.
Harvesting
The fruits dry and split when ripe.
Color: Brown/Copper, Green. Type: Siliqua. Length: > 3 inches.
Garden value: Edible
Harvest time: Fall, Summer
Bloom time: Spring, Summer
Edibility: The foliage is edible raw or cooked but when cooked can emit an unpleasant odor.
Storage & Preservation
Fresh Waltham 29 heads store best unwashed in perforated plastic bags in your refrigerator's crisper drawer at 32-35°F with high humidity. Properly stored heads maintain quality for 7-10 days, while tender side shoots should be used within 3-4 days. For longer storage, blanch florets in boiling water for 2-3 minutes, shock in ice water, drain thoroughly, and freeze in sealed bags for up to 12 months. The sweet, nutty flavor of Waltham 29 makes it excellent for fermentation – try making broccoli kimchi or adding to mixed vegetable ferments. You can also dehydrate blanched florets at 125°F for 8-12 hours to create nutritious additions to soups and casseroles.
History & Origin
Waltham 29 was developed at the University of Massachusetts in Waltham during the 1950s as part of a dedicated breeding program to create cold-hardy brassicas for New England's challenging climate. University researchers specifically selected for plants that could withstand frost, resist bolting in temperature fluctuations, and produce abundant side shoots after the main head harvest. This variety was among the first broccoli cultivars bred specifically for extended fall and winter harvest in northern climates.
The 'Waltham' name honors the university's location, while the number designation reflects its position in the breeding program's selection trials. Released to home gardeners in the 1960s, Waltham 29 quickly gained popularity among northern growers who previously struggled with heat-sensitive Italian varieties. Its development represented a breakthrough in making fresh broccoli accessible to cold-climate gardeners throughout the winter months, earning recognition as one of the most significant broccoli breeding achievements for northern adaptation.
Advantages
- +Attracts: The foliage is edible raw or cooked but when cooked can emit an unpleasant odor.
- +Wildlife value: It serves as a host plant for butterflies, moths, flies, sawflies and beetles.
- +Edible: The foliage is edible raw or cooked but when cooked can emit an unpleasant odor.
Companion Plants
Plant Together
Nasturtiums
Acts as trap crop for aphids and flea beetles, repels cabbage worms
Marigolds
Repels cabbage moths and other brassica pests with strong scent
Dill
Attracts beneficial wasps that parasitize cabbage worms
Onions
Repels cabbage maggots and aphids with sulfur compounds
Celery
Repels cabbage white butterflies and improves soil structure
Lettuce
Grows well in broccoli's shade and doesn't compete for nutrients
Spinach
Shallow roots don't compete, benefits from broccoli's nitrogen fixation
Chamomile
Attracts beneficial insects and may improve broccoli flavor
Keep Apart
Tomatoes
Allelopathic compounds inhibit brassica growth and development
Strawberries
Compete for similar nutrients and may stunt broccoli growth
Mustard
Attracts same pests like flea beetles and cabbage root fly
Nutrition Facts
Per 100g serving. % Daily Value based on 2,000 calorie diet. Source: USDA FoodData Central (FDC #747447)
Pests & Disease Resistance
Resistance
Good cold tolerance and resistance to bolting. Moderate resistance to common broccoli diseases.
Common Pests
Cabbage worms, aphids, flea beetles, cabbage loopers
Diseases
Clubroot, black rot, downy mildew, alternaria leaf spot