Sagittaria sagittifolia
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Overview
Sagittaria sagittifolia is an aquatic perennial of pond margins and slow water, growing from tubers and reaching 12-36 inches (30-90 cm) above the surface. Mature emergent leaves are distinctly arrow-shaped, 4-8 inches (10-20 cm) long, held on long triangular stalks, while submerged juvenile leaves are ribbon-like and strap-shaped. In summer it sends up whorled spikes of white flowers 0.75-1 inch (2-2.5 cm) across, each with three rounded petals and a dark purple basal blotch, the male flowers held above the female. The plant spreads by rhizomes and forms overwintering tubers in autumn, long gathered as food and known as swan potato. It roots in mud in still or slow-moving water 2-12 inches (5-30 cm) deep and dies back to the tubers over winter. In warm still water it spreads quickly and can crowd small ponds, so confined planting baskets are often used. Growth depends on full sun and warm, shallow water; deep or fast water and shade reduce flowering and shrink the emergent leaves. Foliage collapses after the first hard frost and regrows from tubers in spring.
Native Range
Sagittaria sagittifolia is native across Europe and temperate Asia, from Britain east to Japan, growing in ponds, ditches, canals, and the shallow margins of slow rivers. It occupies still or slow fresh water over mud.Suggested Uses
Grown in pond margins, bog gardens, and the shallow shelves of wildlife and ornamental ponds, set 12-18 inches (30-45 cm) apart in baskets. Suits naturalising still water and giving cover and food to waterfowl and aquatic insects. Tubers are harvested as an edible crop in some regions.How to Identify
Appearance
Size & Dimensions
Height1' - 3'
Width/Spread1' - 2'
Reaches mature size in approximately 2 years
Bloom Information
Flowering runs from July into August, with whorled spikes of white three-petalled flowers rising above the foliage. Male flowers occupy the upper whorls and female flowers the lower. Bloom continues over several weeks in warm, sunny conditions.
Detailed Descriptions
Foliage Description
GreenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grow in full sun in still or slow-moving fresh water 2-12 inches (5-30 cm) deep over a mud or loam bottom. Plant tubers or divisions in spring into pond soil or aquatic baskets, which keep the rhizomes from overrunning a small pond. The plant depends on warm water and ample light; shade and deep or moving water reduce flowering and shrink the emergent leaves. Feed sparingly with aquatic plant tablets in nutrient-poor ponds. Foliage dies back after frost, and the tubers overwinter in the mud unharmed in USDA zones 5 through 11. Lift and divide congested clumps every few years to control spread.Pruning
Remove yellowing or frost-damaged leaves at the waterline through the season to keep the planting tidy. Thin spreading rhizomes in spring to limit the colony. No woody pruning applies.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
early spring
Container Growing
✓ Suitable for container growing
Minimum container size: 3 gallons