Skip to main content

Mammoth Sandwich Island Salsify

Asteraceae

Mammoth Sandwich Island is a salsify, Tragopogon porrifolius, a biennial in the aster family grown for its roots. Oregon State University suggests it for trial and describes salsify as a hardy vegetable needing about 150 days, with roots that are not injured by slight freezing. It is not closely related to scorzonera (black salsify). Key facts: 150 days to maturity from seed, 1–2" spacing.

Updated September 11, 2026 · Backed by 4 cited sources
Overview

At a Glance

The essentials first: timing, light, spacing, seed-starting, container fit, and overall size.

Days to maturity
150 days
from seed
Spacing
1–2"
between plants
Planting window

Zone Planting Guide

Switch zones to see whether this plant is a strong fit, what frost timing looks like, and any extra notes worth planning around.

This card updates instantly with viability, frost timing, and any planting notes for your selected zone.

Care

Growing Guide

Everything in one place: seed starting, transplant timing, watering, soil, and structural support.

Moisture
Watering
Weekly1"
Common questions

Salsify (Mammoth Sandwich Island) FAQ

Every answer is assembled from this cultivar's own record, so the figures match the rest of the page.

How many days to maturity for Mammoth Sandwich Island Salsify?

Salsify (Mammoth Sandwich Island) takes 150 days to reach maturity from seed.

How far apart should you plant Mammoth Sandwich Island Salsify?

Space Salsify (Mammoth Sandwich Island) 1–2 inches apart, with 10–15 inches between rows.

How much water do Mammoth Sandwich Island Salsify need?

Salsify (Mammoth Sandwich Island) needs 1 inches of water a week, counting rainfall.

How do you start Mammoth Sandwich Island Salsify from seed?

Sow seed straight into the garden.

When is Mammoth Sandwich Island Salsify in season?

Salsify (Mammoth Sandwich Island) is a cool-season crop, in season during spring and fall in most regions. Plants reach harvest 150 days after sowing and prefer temperatures below 75°F.

Feeding & picking

Nutrition & Harvest

How hungry the plant is, what ripe harvest looks like, and how long the crop keeps after picking.

Timing
Harvest

Roots tolerate slight freezing, so harvest can run past first frost.

Stay in the loop

Planting reminders for Salsify (Mammoth Sandwich Island)

Frost warnings, zone-specific timing, and seasonal nudges -- sent only when there's something to act on. Free, unsubscribe anytime.

Get Personalized Planting Reminders

Frost alerts, zone-specific tips, and seasonal guidance. Free, unsubscribe anytime.

For zone-specific tips
What you'd like to receive (optional):

By subscribing you agree to our privacy policy. We won't sell your data. Unsubscribe link in every email.

What you'll need

Growing Supplies

Hand-picked for your Salsify (Mammoth Sandwich Island), with the extension research behind every recommendation.

Mulch / landscape fabric

Nearly every garden benefits from mulch for weed suppression, moisture conservation, and soil temperature moderation. For most home gardeners, quality organic mulch is the better buy over landscape fabric.

Source: Penn State Extension; Wisconsin Horticulture; Illinois Extension

Our pick

Cleaned Wheat Straw Mulch (3 cu ft, ~20 lbs)

Thoroughly cleaned wheat straw at 3 cubic feet, marketed specifically for vegetable gardens rather than animal bedding or decoration. Better per-pound economics than the 1 cu ft option, with the same extension-recommended material. Strong sales volume (2K+ bought past month) supports product consistency.

paid link ?When you shop on Amazon using this link, SoilStack earns a small commission at no extra cost to you. It's how we keep the site free and the calendar ad-free. Every product on this page was hand-selected based on university extension research. When you shop on Amazon using this link, SoilStack earns a small commission at no extra cost to you. It's how we keep the site free and the calendar ad-free. Every product on this page was hand-selected based on university extension research.
View on Amazon

Drip irrigation / soaker hose kit

Every gardener benefits from putting water at the root zone instead of on the leaves, because drip and soaker systems reduce foliar disease pressure by limiting leaf wetness and soil splash. A quality kit should include a backflow preventer, filter, pressure reducer, and UV-resistant tubing.

Source: Iowa State University Extension; Colorado State University Extension; UMass Extension

Our pick

Complete Garden Drip Irrigation Kit

Designed for beginners with a step-by-step setup guide. Adjustable emitters, both tubing sizes, and all connectors included.

paid link ?When you shop on Amazon using this link, SoilStack earns a small commission at no extra cost to you. It's how we keep the site free and the calendar ad-free. Every product on this page was hand-selected based on university extension research. When you shop on Amazon using this link, SoilStack earns a small commission at no extra cost to you. It's how we keep the site free and the calendar ad-free. Every product on this page was hand-selected based on university extension research.
View on Amazon

Row cover / frost blanket

Row cover adds frost protection, speeds early growth, and physically excludes insect pests without spraying. Look for spun-bonded fabric with a stated weight and frost rating, UV resistance, and enough width for hoops or low tunnels.

Source: University of Maryland Extension; University of New Hampshire Extension; Colorado State University Extension

Our pick

Frost Blanket (10'x30')

Thicker 1.2 oz fabric rated to protect down to 28°F. Covers 300 sq ft — enough for multiple raised beds in a single sheet.

paid link ?When you shop on Amazon using this link, SoilStack earns a small commission at no extra cost to you. It's how we keep the site free and the calendar ad-free. Every product on this page was hand-selected based on university extension research. When you shop on Amazon using this link, SoilStack earns a small commission at no extra cost to you. It's how we keep the site free and the calendar ad-free. Every product on this page was hand-selected based on university extension research.
View on Amazon

Garden shade cloth

K-State Research and Extension and University of Maryland Extension recommend shade cloth as a heat-management tool for vegetable gardens, with 30 percent shade rating most effective for tomatoes, peppers, and fruiting crops, and 40 to 50 percent for protecting heat-sensitive greens during hot summer months. University of Delaware research found 30 percent black shade cloth tripled marketable yield for bell peppers compared to unshaded plants, and Purdue trials showed shade cloth reduced maximum daily temperatures by 8 to 10 degrees Fahrenheit. Choose knitted polyethylene with reinforced grommets every 18 to 24 inches, mount on hoops or a frame with open sides for airflow, and remove or vent during prolonged wet weather to avoid increased humidity in the canopy.

Source: K-State Research and Extension; University of Maryland Extension; University of Delaware Cooperative Extension; Purdue University Extension

Our pick

30% Sun-Block Shade Cloth (6x10 ft)

Same 30 percent rating in the typical home-garden size that fits a 4 by 8 raised bed plus working overhang. Knitted polyethylene with grommets for tie-down. Strong volume signal (3.8K reviews) supports consistent product quality across orders.

paid link ?When you shop on Amazon using this link, SoilStack earns a small commission at no extra cost to you. It's how we keep the site free and the calendar ad-free. Every product on this page was hand-selected based on university extension research. When you shop on Amazon using this link, SoilStack earns a small commission at no extra cost to you. It's how we keep the site free and the calendar ad-free. Every product on this page was hand-selected based on university extension research.
View on Amazon
As an Amazon Associate I earn from qualifying purchases. These are Amazon affiliate links -- if you buy through them, SoilStack earns a small commission at no extra cost to you. It's how we keep the app free and the calendar ad-free. We only link products that match what the research says you actually need.
Internal links

Mammoth Sandwich Island Salsify Planting Dates by Zone

Jump to your USDA zone for frost dates, start-indoors timing, and a full monthly planting calendar.

Ready to grow Salsify (Mammoth Sandwich Island)?

Get a personalized planting schedule based on your exact zone with frost dates, task reminders, and feeding plans.

Start Your Garden Plan