Vegetable / Cool season
Spinach
Cold-soil green that quits the moment days get long
Plant out byApr 6zone 6
- Family
- Amaranth (Amaranthaceae)
- Sun
- Part sun (4+ h)
- Difficulty
- Some care
- Days to harvest
- 40-50 days
- Spacing
- 4 in apart, rows 12 in
- Pot size
- 2 gal pot (great in pots)
- Frost
- Hardy
- Start
- Direct sow
- Water
When to plant
Showing .
Averages for a typical garden in the region. Your local frost dates may differ by 2-3 weeks, check a local source.Too late this year (try fall)
In zone 6, sow or plant outdoors Mar 9 to Apr 6; sow again for fall Aug 25 to Sep 22. Average last frost Apr 20, first fall frost Oct 20.
Units
Spinach is a race against the calendar. You sow it in cold soil and it sits there looking like nothing for a week or two. Then it grows quickly, right as the days start getting long. Once days pass about 14 hours or the weather tops 75 degrees F, the plant stops making leaves and sends up a flower stalk. The leaves turn bitter within days. That is the main thing that goes wrong, and it catches almost everyone the first year.
The fix is timing, not effort. Get seed in as soon as the soil can be worked and reaches about 40 degrees F, which in most places is several weeks before your last frost. Mature plants shrug off frost down to around 15 degrees F, so a cold snap in early spring is not a crisis. A fall sowing is often the better crop, because the plants grow into shorter, cooler days instead of fighting them.
In a pot, spinach wants 8 to 10 inches of soil depth, since it grows a taproot. Pots have one extra trick: you can drag them into shade when a warm week hits. My first spring crop bolted the week I left for a trip. The fall row in the same bed gave us salads until Thanksgiving. Pick the outer leaves and let the center keep going. Wash them well, since the crinkly kinds hold onto grit.
Things to consider
- Days longer than about 14 hours push spinach to bolt no matter how well you water, so a late spring sowing is a gamble in most areas. Slow-bolt varieties buy a little time, not a whole summer.
- Seed sprouts poorly in hot soil. For a fall crop, wait until the soil has cooled to 70 degrees F or less before you sow, even if the calendar says you could start sooner.
- Leaf miners leave pale winding trails inside the leaves. Pinch off marked leaves as soon as you see them and keep row cover over young plants. Downy mildew can also turn up in long damp spells.
Good neighbours
Pests to watch for
AphidsLeaf miners
Questions about growing spinach
Why did my spinach flower before I picked much?
Long days and warm weather tell spinach its season is over, and the leaves turn bitter soon after the stalk appears. Pull the plant and use what is left before it gets worse. Next round, sow a few weeks earlier in spring, or skip spring and try a fall planting instead. Pinching off the flower stalk and keeping the soil moist can slow things down, but it rarely stops them.
Can spinach handle snow and frost?
Grown plants handle frost down to about 15 degrees F, which is why fall spinach often keeps going into early winter. Young seedlings are softer. If a hard freeze is in the forecast while they are small, throw an old sheet or row cover over them for the night and pull it off in the morning once the sun is up.
How many spinach plants fit in one container?
An 8 to 10 inch pot holds one full-size plant. A wider window box can take plants about 4 inches apart for baby leaves, or 6 inches apart if you want bigger ones. Keep the soil evenly moist, because a pot that keeps drying out stresses the plants. Sow a new container every couple of weeks in cool weather and you will rarely run short.
Save this crop
Pin it to a garden board so it is there when planting time comes round.
Similar crops
Sources
General guidance for home gardens. Frost dates are averages for a zone or region; check a local source (in the US your county extension office) for local timing.