Growing at Glebelands
At Glebelands, we try to produce a mixture of salad leaves all year round. Many salad leaf plants, although they will not actually grow in the shorter days of winter, can still be harvested from the glasshouse and polytunnel during this period provided they are not actually frozen, so it is the available space under cover that constrains the amount that can be picked.
The salad leaf mix varies throughout the year, with an emphasis on lettuce varieties in the summer, and more hardy leaves like Winter Purslane (Claytonia) and Endive “extra fine” in the winter. Many Oriental Brassicas and Rocket can be picked for most of the year, except when conditions are very hot.
Colours are mostly many shades of green plus some reds and purples, but orange and yellow Nasturtiums and blue Borage flowers can provide extra colour in the summer.
At Glebelands, we often sow salad leaves in modules for transplanting, rather than sowing seeds directly into the soil:
1. gives plants head start over weeds
2. enables more intensive production, especially under cover where space is limited – for example, can let previous crop stay in ground for longer before transplanting next crop, or can let soil rest longer between crops.
3. allows sowing earlier in season to transplant outdoors when conditions warmer.
4. gives longer time for seedbed preparations – especially useful in spring – for example, we can carry out stale seedbed technique (encourage weed germination which is then cultivated prior to planting)
However, there is the extra cost of compost involved, and transplanting time.
Many of the Oriental Brassicas can grow quite big if grown as single plants, but we prefer to multi-sow (a couple of seeds per module) as this saves time and provides a large amount of small leaves rather than a few large. One exception is Mizuna, which can become very large, and which is sown into seed trays, then “pricked out” when large enough into individual cells, to plant at about 1 month. The large leaves are good for winter salad.
Winter Purslane is multi-sown, but only very few seeds per module as the leaves can become quite big.
Outdoor environmesh “tunnels”
We transplant salad leaves into low-cost “tunnels” made from blue water pipes joined with irrigation pipes and covered with environmesh held down by jaw clamps
1. allows protection against pests, especially flea beetles (holes make crop unsellable), aphids and birds (pigeons). Nb environmesh needs to be of a fine enough grade to give protection against flea beetle.
2. allows for easy irrigation – keeping the Oriental Brassicas cool & moist can sometimes delay bolting in hot conditions and this can also help against flea beetle. Green shade netting can be put over the mesh in very hot conditions.
3. avoids plants disappearing under sea of weeds in field by defining planting area, which can be cultivated
4. can also provide a degree of protection in winter, especially against destructive winds. Horticultural fleece can be added for additional protection against cold - less likely to be blown away or destroyed by animals in the tunnels
Notes on individual salad leaves:
Can begin sowing in January and February, though growth slow which makes them prone to disease – usually still harvesting overwintered leaves at this stage. Rocket is probably best for early sowings.
Then sow in March to plant under cover (perhaps replacing overwintered crops gone to seed etc), and for earliest “tunnels” outside. Can take 3 weeks from sowing to planting at this stage, though usually 2 weeks max later in season.
Then sow in succession- roughly every 2 weeks - for planting outside until late summer (August). Can be ready 3-4 weeks from sowing, depending on weather. Can leave summer sown plants to overwinter outside: in south of England and in mild winters here, some plants can survive outside, under tunnel with fleece, but the quality is sometimes not great – for example mustards can become coarse.
We sow in Sept for planting 2 weeks later under cover for overwintering – will be ready from October when outdoor plants finished.
Varieties – there is a large variety of Oriental leaves, increasing all the time. We have tried a few.
Mustards (Brassica juncea):
Green in Snow – serrated edged, green, very hardy – does best in early spring and autumn
Osaka Purple – red veins, good in spring
Giant Red – better than O Purple for overwintering
Golden Streaks – feathery leaves, good all year round, except at the height of summer – has appealing taste
Ruby Streaks – red version of above, grows faster and bolts more quickly than Golden Streaks in warmer conditions, but excellent for winter colour
Sessantina and Serifon (Tamar)– tried for first time in 2008 – bolted very quickly in warmer weather, but good for spring sowings
Saisai (Leaf Radish) – tried for first time in Sept 2008 –very fast growing and tastes fine, but seeds hard to get
Komutsana (Brassica rapa Perviridis Group) – not as good in mixed salad leaf, but large leaves good for “stir fry” mix
Tatsoi –(B. rapa var. rosularis) – soft leaves prone to slug damage, but otherwise great
Mizuna (B. rapa var. nipposinica)– very useful in winter mixes
Mibuna – non-serrated version of Mizuna, and seems less prolific, but leaf shape a nice contrast to other leaves
Shungiku (Xanthophthalmum coronarium) (not a brassica) – ok, but fiddly to harvest
Note on spacings: Under cover in winter: always a balance between trying to make the most of this limited space, and avoiding overcrowding and stressed plants.
Outside: 6 rows/bed, plants 6” apart in rows seems to work ok in the 4ft wide mesh tunnels – allows for hoeing between plants when small
Rocket (Eruca versicaria)
Direct sow, or sow as Oriental Brassicas, though usually faster growing, but can sow earlier in spring and later in autumn.
Winter Purslane/Claytonia (Montia perfoliata)
Very useful in winter, as hardier than many other leaves. Sow in Aug/Sept for transplanting 4 weeks later – August sowings can be planted outside to harvest from Oct through to the following spring (depending on weather), and Sept sowings planted under cover.
The flowering stems are also edible when small.
Needs cool temps to germinate – will probably need to be germinated in shade, esp if Aug or Sept hot. Important to protect from slugs.
Chicory (Cichorium intybus) & Endive (Cichorium endivia)
Huge choice from Seeds of Italy, and have only experimented a little. Need to add to salad mix sparingly – although this very much depends on taste, and they seem to be much less bitter in winter.
Best Chicory so far: Chicory Spadona – strap shaped leaves, hardy, can grow most of the year. Am trying a red variety of Chicory with long, pointed leaves under cover autumn 08.
Best Endive: Extra Fine de Louvier (Organic Gardening Catalogue) – finer leaved than Pancalieri yet still hardy – frilly leaves great for salad mix (supermarket salad packs use shredded chicory & endive).
Have tried Scarole types of Endive – too big for salad mix, but can sell whole as winter lettuce substitute to those with acquired tastes.
Amaranth (Amaranthus spp.) and Perilla (Perilla frutescens) (aka Shiso)
Can be sown in summer as a change from lettuce. Both available in red or green varieties: have found Red Perilla much better, both colours of Amaranth ok, but red leaves more striking in salad.
Both need min. 18 °C to germinate, and Perilla needs light to germinate.
Have successfully multi-sown both in modules and grown Amaranth as individual large plants. Need protection from slugs.
Perennial – can sow from seed, then pick out best plants, divide and transplant them the following year. Can also be transplanted under cover for winter. Relatively hardy - can be harvested into autumn outside.
Keep well weeded – plant far enough apart to wheel hoe between - and remove flowering stalks. Nice lemony taste, adds variety to salads (and not a brassica!).
Best picked for salad leaf while leaves small and soft, but larger leaves for soup etc. becoming gradually more popular.
Broad Leaved Sorrel (Rumex acetosa) is best for salad leaf production, though we also grow Buckler Leaved (R. scutatus) – this is much more fiddly to pick, and is used a ground cover around the site! Buckler leaved seems to prefer a drier and sunnier site than Broad Leaved which like summer shade. Watch out for labels, as both varieties can be called French Sorrel!
Have had problems with dock beetles on Sorrel at Glebelands (beautiful vivid bright green beetles) making lots of holes- have tried mesh covers, but doesn’t seem to help. However these seem to be declining anyway – maybe because we have less docks too (gradually dealing with ones we inherited)
Can be 50-80% of salad leaf mix in summer – described on separate page
Nasturtiums (Tropaeolum majus)
Need to be an organic variety - now available from Tamar and Demeter seeds. Can sow some in modules at end of March for early flowers, then direct sow outside. They also usefully self seed beneath the remains of the previous year’s plants which can protect them in the spring
Borage (Borago officinalis) – self seeds readily from a few plants – fiddly to pick (pull petals from hairy sepals) but blue colour looks great in salad mix
General cultivation notes:
Hoe between plants when small to avoid weed competition – makes harvesting much easier. Pre-planting weed strikes, for example with flame weeder useful good too.
In dry conditions, try to keep soil surface moist to avoid flea beetles on Rocket and Oriental Brassicas – when hoeing required, do so on a windy day when soil will dry out quickly, then irrigate as soon as weeds dead.
Water sparingly in winter under cover, best from below with T-tape
In general, need to be ruthless about quality – don’t try to sell anything you wouldn’t buy yourself.
Can either cut whole plant across, or cut individual (largest) leaves.
Usually it is necessary to cut largest leaves anyway so plant will keep on producing leaves. Cutting whole plants means longer to wait before next cut as small leaves are also harvested. In winter we tend to cut largest leaves of red and green mustards, to keep them going longer.
Golden and Ruby Streaks regrow very quickly, so can be cut whole anyway. Mizuna is easier to cut whole, but we often cut single leaves in winter..
Cool leaves in water after picking, especially in summer, when they can wilt very quickly. Wind can dry out cut leaves quickly, so leave in a sheltered spot.
Can harvest 3-15kg per hour, depending on nature of salad mix – ie Lettuce quick to cut in summer, individual mustard leaves much slower in winter.
Yields vary hugely, depending on the time of year and whether the plant will regrow