Gadenin日本語Get the appHeading types are a different crop
Lettuce that forms a solid head and lettuce that does not are close to two different crops in practice. Heading types need a long cool run, and heat partway through means no head at all. Leaf types have far less of that constraint and are ready in half the time.
In a home garden it is almost always the heading types that go wrong. To form a head the plant has to build about twenty outer leaves and then keep going through weeks at 59 to 68F (15 to 20C). Because so few parts of the year offer that, sowing late turns directly into failure.
| Type | Head | Planting to harvest | Difficulty |
|---|---|---|---|
| Crisphead | Firm, solid | Eight to nine weeks | High |
| Romaine | Upright, semi-heading | Seven to nine weeks | Moderate |
| Butterhead | Loose, soft | Six to seven weeks | Low |
| Loose leaf | None | Four to six weeks | Low |
Telling the types apart and what each is for
On a seed rack they are sorted by color and leaf shape, but the three things that actually matter when choosing are whether it heads, whether the leaf is thick, and whether you can pick it leaf by leaf.
If you are unsure, count the cool weeks you have available. Two months of days around 60F (15C) after planting means a heading type is realistic. One month means a leaf type. Look at when the bed will be free before you buy the seed and you will not go far wrong.
- Crisphead A firm head of thin, watery leaves. This is the one to grow for crunch in a salad, but it has the narrowest set of conditions of any of them.
- Red loose leaf Non-heading, with frilled leaves that color red at the tips. The color deepens in the cold, so an autumn sowing gives you a better looking plant.
- Green loose leaf Non-heading and plain green with frilled edges. Fast growing with a wide sowing window, so it slots into gaps between other crops.
- Romaine Upright leaves forming a tall, half-closed head. The leaf is thick enough to cook, so it suits a household that does more than salad.
- Cut-and-come-again leaf Picked leaf by leaf from the bottom up over a long period. Per plant it yields more than any other type.
Two seasons: spring and autumn
Because it grows best at 59 to 68F (15 to 20C), the natural windows are spring and autumn, when the temperature passes through that band. In spring you are growing into rising temperatures and racing the heat. In autumn you are growing into falling temperatures, so sowing late means the plant stops before it fills.
| Sowing | When | Harvest | Where it goes wrong |
|---|---|---|---|
| Spring | Late winter to early spring | Late spring to early summer | Heat at the end makes it bolt |
| Late summer | Late summer | Mid to late autumn | Too warm to germinate |
| Autumn | Early autumn | Late autumn to early winter | Sown late, the head never fills |
If you want two crops from one bed, put loose leaf in the spring slot and a heading type in the autumn one. Heading lettuce in spring is the harder ask.
The window moves by about a month with climate
In a mild garden you can sow later in autumn but have very little room in spring. In a cold garden it is the reverse, and late spring into summer is the main season. Using the same calendar everywhere means mild gardens fail in spring and cold gardens fail in autumn.
| Climate | Spring sowing | Autumn sowing |
|---|---|---|
| Mild | Late winter to early spring | Early to late autumn |
| Average | Late winter to mid spring | Late summer to early autumn |
| Cold | Mid spring to early summer | Mid to late summer |
Choose varieties by bolt resistance and season
Packets say which season a variety is for. Get that wrong and good growing will not save it. A spring sowing runs into heat and long days, which is what makes bolt resistant varieties worth paying attention to.
For autumn the priority reverses: you want an early variety that will fill a head at low temperatures. The later you sow, the more that matters. Check the sowing window on the packet against the date you actually intend to sow.
- In spring, choose bolt resistant A variety selected to bolt late buys you anything from a few days to two weeks against rising temperatures, and that margin is often the whole crop.
- In autumn, choose early You want the head finished before the cold arrives, so pick something ready in about eight weeks from planting. Late varieties may not make it.
- In summer, switch to leaf types If you want to pick through the hottest weeks, give up on heads and grow loose leaf or cut-and-come-again types under shade.
What to grow the first time
For a first attempt, an autumn sowing of loose leaf lettuce is the reliable choice. The temperature suits germination without any intervention, pest pressure is falling, and even a poor result gives you thinnings to eat. Learn the spacing and the germination there, then move on to heading types.
- Mix the two in one bed Slot a loose leaf plant between heading lettuces spaced twelve inches apart. You pick the leaf type before the heads need the room, and nothing is wasted.
- Sow the same variety twice Sow again ten days later. The harvests do not collide, and if one sowing is caught by the weather you have not lost everything.
- Buying plants is not cheating Germinating in the heat is the hard part, so for an autumn crop it is perfectly reasonable to buy plants and start at planting. Choose young ones with four or five true leaves.
Avoid stretched, leggy plants and any with yellowing lower leaves. The outer leaves never develop and they do not head up.