You labored so onerous to seed, plant, water, and have a tendency your lettuce patch, solely to seek out that your tender lettuce has all of the sudden spiraled upward right into a bizarre cone form. As soon as lettuce vegetation “bolt” or go to seed, they develop into virtually inedible. Bolting lettuce is a significant downside for any salad lover as a result of the leaves flip bitter and difficult, and the plant begins channeling its power into flower and seed manufacturing fairly than tasty leaves.
The unhealthy information is you’ll be able to’t reverse bolting as soon as it begins. However the excellent news is that bolting is totally preventable, and you should use many backyard hacks to delay your lettuce harvests and stop vegetation from going to seed. Let’s dig into the prime 10 causes and options for bolting lettuce.
What’s Bolting?
Bolting is gardener jargon for “going to seed.” When a plant bolts, it elongates its kind, sending up a tall central stalk that “bolts” towards the sky and develops flowers. These flowers finally flip to seeds, pulling the plant’s power away from root or leaf manufacturing.
That is unhealthy information for vegetable growers as a result of a lot of our favourite crops, like lettuce, kale, radishes, carrots, spinach, and chard, develop into inedible after bolting. It’s not that they’re harmful, however fairly that the leaves and roots change kind and infrequently develop into bitter or robust as soon as seed manufacturing begins.
Bolting possible alerts that your crop goes to die. Whereas perennial vegetation produce flowers and seeds all through their lifecycle, annual and biennial vegetation expire after copy. Most backyard greens are annuals or biennials that naturally finish their lifecycle after one or two seasons. Some species have inherently shorter lifespans, whereas others are reduce quick by environmental elements.
A plant may go to seed attributable to drought, transplant shock, pests, ailments, crowded spacing, and different types of plant stress. A severely pressured plant primarily says, “Oh no! I’ll die quickly, so I need to make as many infants as attainable to delay my species.” In a last-ditch effort at copy, a pressured crop will bolt.
Vegetative vs. Reproductive Development
Like people, vegetation have two main life phases. First, they develop and develop their bodily techniques, then change to reproductive mode. In flowering vegetation, these are referred to as the vegetative and flowering phases.
Throughout vegetative progress, vegetation dedicate power to creating their roots, stems, and leaves. When the day size switches, photoperiod-sensitive vegetation (like lettuce) change their power to gasoline flower and seed progress. The shift from vegetative to reproductive progress sometimes correlates with an elongated form and extra bitter leaves.
Gardeners can see the shift to reproductive mode because it occurs. In heading lettuce, the outer leaves will begin to unfold, and the middle of the pinnacle will produce a flowering stalk. In leaf lettuce, the flowering stalk causes the entire plant to get taller. Leaf manufacturing halts in each cases, and the remaining leaves tackle a bitter style, signifying the hormonal shift within the plant’s tissues.
How Do I Maintain My Lettuce From Bolting?
Bolted lettuce is simple to forestall however troublesome to cease. The best prevention is to develop lettuce within the cooler shoulder seasons of spring and fall. If you wish to develop leafy greens in the summertime warmth, choose bolt-resistant seed varieties, use shade fabric or row cowl, apply companion planting, and harvest the crops younger.
Lettuce mostly bolts attributable to huge temperature fluctuations (significantly warmth waves) and a change in day size (longer days sign to the plant that it’s time to breed). To utterly keep away from bolting issues, it’s essential to supply vegetation with sufficient water, vitamins, spacing, and safety from stressors like pests or ailments.
Pressured lettuce vegetation usually tend to bolt below nearly all circumstances. Decreasing plant stress is essential. Trendy bolt-resistant seed varieties additionally make it simpler to increase your lettuce harvests.
10 Causes for Lettuce Bolting
It is vitally irritating when your lettuce begins to bolt prematurely. The sudden progress of a tall flowering stalk causes the beforehand juicy, refreshing greens to show bitter and difficult. Listed below are ten potential causes for bolted lettuce and easy methods to repair them for extra profitable future crops.
1. Temperature Fluctuations
Lettuce is a cool climate crop that enjoys the coolness of spring or fall. When temperatures climb above 75°F, the vegetation will possible develop into pressured and go to seed.
These tender salad greens are additionally delicate to huge temperature dips. Whereas lettuce enjoys chilly climate, it can’t deal with sudden chilly snaps.
The Resolution: Use a row cowl in chilly climate and shade fabric in scorching climate. These agricultural materials assist average the temperature near the bottom, making a extra constant microclimate that buffers your lettuce towards climate extremes. You may set up metallic wire hoops over your lettuce beds or just “float” the material on prime of the greens.
As a bonus, many row covers and shade cloths dual-function as insect netting. They bodily exclude pests from the tender leaves, making your pest management efforts far simpler. You should definitely securely anchor the material in place with sandbags or easy stones that received’t rip the supplies.
2. Lengthy Day Size
Lettuce is a long-day plant that enters its bloom cycle when it receives greater than 12 hours of daylight. Recall that the essential strategy of photosynthesis requires daylight, water, and carbon dioxide to create power for plant progress. The quantity of daylight instantly impacts how the plant responds to its surroundings and grows in several phases of its life.
Photoperiod sensitivity impacts how a plant responds to darkness or gentle. This tendency is hard-wired right into a species’ genetics. Botanists used to suppose that the size of the daylight decided when a plant would kind flowers, however trendy scientific experiments have confirmed that the size of darkness is definitely the best determinant of plant flowering.
Within the case of lettuce, the vegetation keep of their vegetative (leaf-producing) state once they obtain greater than 12 nighttimes. Seasonally, this occurs within the spring and fall within the northern hemisphere. However when the summer season days start to get longer, the shorter nights sign to the plant that it’s time to reproduce, so it sends up a flower stalk to provoke pollination and funnel its power towards seed manufacturing.
From the plant’s perspective, it does precisely what it was designed to do: survive and reproduce. However from a gardener’s perspective, this irritating shift means we received’t get to take pleasure in summer season salads. You may’t change the quantity of daylight, however you should use shade fabric to change the quantity of sunshine the plant receives.
The Resolution: Use shade fabric and develop bolt-resistant varieties like ‘Vivian’ or ‘Nice Lakes 118’ that naturally face up to the summer season shift in day size. In catalogs, these seeds are sometimes labeled as “bolt-resistant,” “warmth tolerant,” or “summer season lettuce.”
Plant breeders have discovered methods to scale back lettuce photoperiod sensitivity via hybridization and conventional breeding. Relaxation assured, bolt-resistant cultivars are non-GMO; they’re NOT genetically modified. Slightly, they’re crossed and chosen for traits that stop untimely flowering.
3. Transplant Shock
In case your lettuce bolts whereas the vegetation are nonetheless very younger, it’s in all probability attributable to transplanting stress. Transplant shock is a typical reason behind bolting as a result of vegetation are all of the sudden uncovered to harsher climate, extra intense daylight, much less water, and total rougher circumstances in comparison with what they skilled whereas in seed trays.
If you concentrate on a child all of the sudden being thrust from its crib out into the good huge world, you’ll be able to see why change is so intense and tough on a younger plant. Even adults get sick when shifting from drastically completely different areas, like from a heat seashore to a frigid mountaintop.
With no correct adjustment interval, child lettuce might panic and suppose it can die. In its ultimate effort to attain its sole life function (copy!), the tiny lettuce plant sends up a stalk and funnels all of its remaining power into producing seeds.
The Resolution: Totally harden off your seedlings earlier than transplanting. This enables them to slowly acclimate to outside circumstances, lowering the sudden temperature swings they might expertise when moved from a nursery or windowsill into the backyard. To harden off, start by putting seedlings open air in a protected space like a patio or porch for 8-10 hours per day. Carry them inside on the primary few nights, then allow them to keep open air in a single day for a few week. You may slowly reduce on water, however not a lot that the vegetation dry out.
When it’s time to transplant, use a row cowl or chilly body to guard seedlings from the chilly nights of early spring. Something you are able to do to buffer them from temperature extremes, the higher.
When planting, decrease root disturbance by dealing with the infants rigorously. Keep away from smushing or compressing the delicate roots, as this will trigger extra shock and result in bolting.
Diluted kelp resolution is proven to enhance root institution and stop shock. Sustaining constant moisture is essential within the early phases to make sure the seedlings can anchor roots of their new dwelling. You too can use row covers to average the temperature.
4. Crowded Planting
No person likes to be crammed collectively in a small area, and your lettuce vegetation are not any completely different. The stress and useful resource competitors from overcrowded plantings trigger lettuce to go to seed prematurely. Planting too shut collectively may trigger airflow and illness issues.
Rising extra seedlings in an area could appear to yield extra crops, however this false impression can work towards you. Extra vegetation in a smaller area hinder the expansion of all of the vegetation within the mattress, lowering your total yields.
For those who don’t skinny your seedlings or correctly area your transplants, the lettuce might bolt at a really younger age as a result of it thinks it has reached the top of its life cycle attributable to environmental stress.
The Resolution: Observe the really helpful spacing to your variety- often a minimum of 6” between vegetation for small heads and 8-12” for bigger head lettuce. If direct seeding, skinny just a few days after germination to make sure the seedlings can get a robust begin to life.
5. Stress From Pests and Ailments
The clear theme right here is that stress causes bolting. These vegetation are genetically coded to go to seed at any time when exterior elements set off that their lifespan is over. Not solely do pests and ailments trigger ugly, broken vegetation, however they’ll additionally push lettuce to bolt.
The Resolution: Fastidiously monitor your crops, particularly throughout the early weeks of multinational. A 5-minute night stroll across the backyard will make it easier to keep in tune along with your greens and catch any points early. Lettuce typically will get attacked by aphids and flea beetles. Each might be eliminated with a blast of water or diluted neem resolution.
Companion planting is an effective way to draw helpful insect predators to the backyard. Nice lettuce companions embrace white alyssum, marigolds, onions, and scallions. Plant these on the borders or ends of your beds to repel pests and entice beneficials.
Illness issues might be prevented by sustaining sufficient spacing (to encourage airflow) and watering with drip irrigation or soaker hoses. Keep away from overhead irrigation which will soak lettuce leaves and welcome mould or mildew. Maintain your backyard beds well-amended with microbially wealthy compost. The helpful microorganisms act like an immune system to your vegetation, stopping pathogenic fungi or micro organism from colonizing the roots or leaves.
Total, a more healthy plant is extra resilient to pests and ailments and fewer prone to bolt. Add a lot of wealthy natural matter to your soil, keep constant moisture, and fertilize with a top quality natural slow-release fertilizer on the time of planting.
6. Too A lot Daylight
Lettuce is a good crop for partially shaded gardens. They nonetheless want loads of gentle to thrive and produce vibrant inexperienced (or crimson or speckled) leaves, so don’t plant lettuce in a very shaded space. Someplace with 6-8 hours of direct solar is nice. My favourite place for lettuce is on the east or west aspect of the backyard or anyplace with dappled daylight.
Bear in mind, an excessive amount of shade may trigger stress and bolting. Gradual, leggy progress and pale leaves are widespread in lettuce vegetation that aren’t getting sufficient daylight. They nonetheless want loads of UV rays to maximise photosynthesis and produce wholesome leaf progress that can resist bolting.
The Resolution: Plant your lettuce in {a partially} shaded space of the backyard. These greens do finest with vibrant morning solar and partial shade within the warmth of the afternoon. I really like companion planting lettuce close to the cover of tall-growing crops like tomatoes or trellised cucumbers. Nevertheless, you need to plant the lettuce a minimum of 8-12” from the bottom of the bigger crop to make sure it nonetheless has entry to some daylight.
You too can use shade fabric to guard lettuce from intense summer season sunshine. Bear in mind the day size sensitivity? Lettuce is a long-day plant, that means it tends to bolt when it receives greater than 12 hours of direct daylight. For those who can scale back how a lot gentle lettuce receives throughout the summer season, you stop it from going to seed as rapidly.
7. Poorly Timed Harvest
Generally, gardeners wait too lengthy to select their lettuce. In case your vegetation grew tremendous massive after which bolted, you in all probability simply missed the harvest window. It is a true annual plant that received’t final eternally within the backyard.
You may delay the harvest by utilizing the “reduce and are available once more” harvest method or reducing simply the decrease leaves. If a plant begins to elongate upward barely, it’s planning to bolt. You need to have just a few days to reap it whereas the leaves are nonetheless tasty. Sadly, as soon as it goes to seed, that ship has sailed! Pull the plant and begin one other succession.
The Resolution: Verify the times to maturity (DTM) in your seed packets. Mark in your calendar while you seed the crop, then rely ahead to remind your self when it will likely be prepared. The window of maturity might be a number of weeks lengthy, however it helps to have a heads-up. Extra importantly, you ought to be checking your lettuce frequently.
You too can “reduce and are available once more” by harvesting the outer leaves or reducing the highest of the plant in a dome-like form, leaving the central rising tip intact. The plant will regenerate inside a few weeks. That is nice for a steady harvest of salads.
In case you are rising head lettuce, verify the variability’s typical harvest dimension. Many romaines develop as much as 10” tall and 4” vast, whereas some child lettuce heads are bred to be harvested at a micro 6” diameter. As a substitute of reducing complete rows directly, I like to reap in an alternating sample, leaving each different plant in place to develop a bit of bigger the next week. Lettuce can technically be eaten at any progress stage, however you positively need to catch it earlier than it bolts, or the greens will flip bitter and gross.
8. Water Stress
Drought can rapidly ship your lettuce crop to seed. The stress of low water alerts to the plant that its season is ending and it’s time to breed earlier than it dies. Untimely flowering is quite common for a lot of veggies dealing with drought circumstances.
The Resolution: The succulent, juicy leaves of lettuce unsurprisingly require a good quantity of water. This thirsty, shallow-rooted prefers persistently moist soil. First, make sure your soil is generously amended with compost and natural matter. This helps retain moisture longer, so that you don’t must irrigate as typically.
Subsequent, set up drip traces or soaker hoses in your lettuce mattress instantly after planting. These irrigation traces will provide water straight to the foundation zone of the vegetation with out inflicting any illness points on the leaves.
Keep away from overhead irrigation for those who can. Verify the soil each 2-3 days throughout scorching climate. All the time stick your finger a number of inches within the soil to gauge the moisture degree. In case your pores and skin comes out clear, it’s too dry.
Lastly, mulch is your finest insurance coverage coverage towards water stress and bolting. It not solely retains moisture within the root zone, however it retains the soil temperature cooler in scorching climate. Shredded straw or leaf mulch are nice for tucking round your low-growing leafy greens.
9. Varietal Selection
A spring butterhead cultivar will often bolt for those who plant it in June. Equally, a cold-loving romaine will wrestle in summer season climate. Nevertheless, heat-resistant and bolt-resistant leaf lettuce, like ‘Ezrilla,’ can tolerate higher temperature fluctuations. Discovering the proper selection takes experimentation, however it helps to learn your seed catalog rigorously earlier than ordering.
Greens are bred for particular culinary makes use of and seasonal plantings. Some lettuces weren’t meant for southern climates, scorching summers, or tremendous chilly circumstances. For those who face particular climate patterns, all the time search for varieties suited to these circumstances.
The Resolution: Buy seeds labeled to your explicit circumstances. If you wish to attempt your hand at summer season lettuce, all the time select bolt-resistant varieties and use the above ways, like shade fabric, companion planting, and “reduce and are available once more” harvests to forestall it from going to seed too quickly.
10. Fallacious Season
Clearly, lettuce likes gentle, cool climate. In case you are actually uninterested in coping with bolted vegetation, keep away from rising lettuce within the summertime. Gardening turns into so much simpler while you cease preventing with the pure circulation of issues. If a crop repeatedly goes to flower or fails utterly, it’s an indication that it might be finest grown in a unique season or space of the backyard.
The Resolution: Select heat-tolerant greens for summer season salads, resembling Malabar spinach, orach, purslane, or chard. These crops are naturally resilient in scorching climate and much much less prone to flower within the vibrant solar.
Resume your lettuce plantings in late summer season when the nights start to chill. Alternatively, you’ll be able to develop lettuce in a container in your windowsill.
Last Ideas
The general theme is evident: These vegetation naturally bolt once they get numerous summer season sunshine and warmth as a result of the circumstances sign to the plant that its life cycle is ending. When lettuce encounters intense sunshine, excessive temperatures, overcrowded spacing, or every other stressors, it can go to flower.
The easiest way to forestall bolting is to:
- Develop lettuce in cool climate
- Use shade fabric in scorching climate
- Select bolt-resistant varieties
- Guarantee correct spacing (don’t overcrowd)
- Present constant water
- Harvest on the proper time (don’t wait too lengthy)
- Forestall pests and ailments
- Companion plant beneath taller crops like tomatoes
