Grow Lamb’s Lettuce From Seed | Germination & Temperature

Last updated on October 23rd, 2023 at 08:46 pm

As summer draws to a close, vegetable beds and greenhouses empty out. Now is the time to look for alternatives. For example, you can grow lamb’s lettuce from seed. Here you will find all the important information on sowing, germination period and germination temperature.

• optimal sowing date between mid-July and mid-September
• depending on the variety, harvesting is possible between September and March
• spring sowing also possible
• optimum germination temperature between 16 and 18 °C
• germination period between 10 and 14 days

Sowing and harvesting dates

Field or rapunzel lettuce (Valerianella locusta) is a typical fall vegetable that can be sown between mid-July and mid-September, depending on the variety. Plants sown in July and August can then be harvested in September or October, while later sown tranches are not ready for harvest until November. In principle, even later sowing dates are conceivable, but plant growth stops at temperatures below eight degrees Celsius. Therefore, late-sown lettuce can only be harvested from March or April.

Tip: If you sow the seeds of lamb’s lettuce late in the fall, it is best to do so in a protected greenhouse or cold frame. A raised bed can also be converted into a cold frame by means of a translucent lid. In this way, you extend the sowing and harvesting times.

Variety selection

There is a large selection of field lettuce varieties that are suitable for different sowing dates: You can grow robust varieties such as ‘Gala’ or ‘Favor’ all year round, which are robust, fast-growing and resistant to downy mildew. These varieties, which can be grown year-round, are also suitable for spring sowing. The cultivation of mildew-resistant varieties is also useful for overwintering, and they should also be frost-hardy. Suitable for this purpose are for example:

• ‘Accent’: August to October
• ‘Juwallon’: July to October
• Verte de Cambrai’: sowing August to September
• Vit’: sowing July to October

Proven cultivars for the fall harvest, on the other hand, are.

• Dark green full-hearted
• Dark green full-hearted 2
• Dutch Broadleaf’ (also suitable for spring sowing).

Be sure to harvest overwintering plantings by March at the latest. Lamb’s lettuce begins to flower in April and is no longer suitable for consumption. However, you can leave some plants standing for seed collection and harvest the mature seeds or let them self-sow.

Note: In some variety lists, the red-leaved variety ‘Ovired’ appears, but it is not lamb’s lettuce. Instead, this lettuce is classified as romaine lettuce (Lactuca sativa var. longifolia).

Sowing

As a rule, the seeds are quite germinative and robust, so direct sowing in the bed can be done. To do this, proceed as follows:

Harvest the seed area and free it from weeds.

• thoroughly dig and rake the soil
• cast the seeds in a wide cube
• or sow in rows with 10 by 10 centimeter spacing
• dark germination, therefore cover seeds with 0.5 to one centimeter of soil
• press down soil
• water thoroughly and keep evenly moist

Emerging weeds should be regularly plucked out from the beginning, so that the slower-growing field lettuce is not overgrown by wild weeds. In addition, the soil must always be kept slightly moist and not dry out, otherwise the seeds will not germinate. After emergence, plants that are too close together will be distorted.

Tip: When sowing in early spring or late fall, a protected bed, such as in a greenhouse or cold frame, is recommended due to cooler temperatures.

Germination period and temperature

Lamb’s lettuce seeds germinate best at temperatures between 16 and 18 °C. At this germination temperature, it only takes about 10 to 14 days for the first green tips to peek out of the soil. Seeds also germinate well at temperatures between ten and 15 °C, but less regularly and the average germination period may be a few days longer. Under no circumstances should you sow lamb’s lettuce in summer weather above 20 °C, as the seeds will germinate much more poorly or even not at all.

Note: Lamb’s lettuce generally tends to germinate unevenly, i.e. seeds sown at the same time can germinate several days apart. So don’t reseed immediately if rows are sparse, but be patient.

Preplanting and planting out

You can not only sow lamb’s lettuce directly in the bed, but also grow it in advance. This has the advantage that the germination period is shortened and you can harvest faster. In this way, you can plant the pre-pulled plants in the freshly harvested bed, so you don’t have to wait for the seeds to sprout. And this is how it works:

• Get soil press bales or seedling cubes
• press one seed per cube
• moisten well
• place in a mini-greenhouse or cover with foil
• high humidity ensures faster germination
• do not place too warm (no direct sun!)

As soon as the plantlets have developed at least one proper pair of leaves and the planting bed is prepared, you can put them outside. However, in doing so, accustom them slowly to the new environment.

Tip: Lamb’s lettuce can be grown not only in the garden bed, but also in window boxes on the balcony or terrace.

Frequently asked questions

How do you fertilize lamb’s lettuce?

Lamb’s lettuce is relatively undemanding and therefore does not need to be fertilized, even if the plants are sown in the vegetable bed as an after-crop. The remaining nutrients are perfectly adequate for the fall vegetable, and in addition, plantings that cannot be used can be dug under as green manure in the spring. A soil that is not too rich in nutrients is even advantageous, as the lamb’s lettuce is thus enriched with less nitrate. During the cultivation phase, it is sufficient to weed the weeds and water the plants regularly.

What is the shelf life of lamb’s lettuce after harvest?

You should consume the lamb’s lettuce or rapunzel lettuce as soon as possible after harvest. If this is not possible, the fresh harvest can be stored in the vegetable compartment of the refrigerator for about two to three days. However, the lettuce quickly loses its crunchiness and flavor, and it cannot be preserved – freezing, for example, is not possible. Therefore, sow the seeds at staggered times so that you do not have to harvest everything at once.

Can you harvest lamb’s lettuce more than once?

In fact, lettuce can be harvested multiple times, as long as the leaf rosette is not cut too deeply. If the roots in the soil are intact and an above-ground plant remnant remains, the plantlets will always sprout again. It is also possible to pluck off only individual leaves. However, the prerequisite for this is that the last harvest is not too late in the year, because the plants do not continue to grow at temperatures below eight degrees Celsius.