Why Are My Cucumbers Dying!? Secrets for a Successful Cuke Harvest

Chemical Free Homestead Cucumbers 101 Natural Pesticides Uncategorized

Need Some Advice? Cucumber Growing Tips?

So, there you were, cruising through the spring growing season watching your cucumbers simply flourish. You had one delicious salad with a crisp cucumber, right after you rubbed its small spines off of it in your bountiful garden, and you were hooked. Then, as if disaster struck overnight, the lush, green canopy of young cucumber leaves seems sick. Perhaps they’re pale green or yellow, slightly wilted, there are holes in the canopy, and cucumber fruit and flower production plummets. Alarmed, you rush to Google for all of the possible problems… but you still aren’t sure! First, check to see if you have missed anything in the list below during the growing season; sometimes, failure to thrive can be due to a very small error on your part, and it can be VERY easy to correct in most cases! If not, you may find yourself battling a pest problem or disease; a lot of cucumber pests can be fought with organic, pesticide free methods, such as dish soap or diaotomaceous earth (yes, it works! It saved my potatoes from an unknown pest last year!). Cucumbers are quite the hardy little plants, so just be sure to take the proper action quickly, and you should see your cuke plants bounce right back!

  • Are you watering incorrectly? We have all done it. We’ve sprayed our plants during the heat of the day, we’ve soaked the foliage, we’ve used sprinklers… we’re human, we’re BUSY, and well… crap happens! If you are doing these things, do your plants a favor and water them the proper way. Water either during the early morning or late evening, preferably during the morning. Slugs love moisture, so a night watering can be an invite to a luxurious cucumber dinner. Let’s avoid those slimy critters. Watering during the heat of the day can be stressful for plants and they may not take up much water before it dries up; also, wet foliage will suffer in sunlight. It burns the leaves, much like wet skin burns much faster than dry. By using an irrigation rather than spraying method, more water gets underground to the roots.
  • Is the soil amended properly for cucumbers? Cucumbers prefer a rich, warm, fertile soil with a PH of 6.0 up to 7.6. If the soil is poor and depleted, you might need to feed them with some fertilizer. Ensure that the soil is well drained. Most plants don’t like soggy roots, and a combination of these problems could result in stunted, water logged plants that struggle to thrive.
  • Are you taking care of pests before they become a problem? You’ve probably noticed a slug here, a squash bug there, maybe a vole nibbling here and there, a cucumber beetle might have stopped in for a visit. While one or two of these pests is not the end of the world, it should set off an alarm that causes you to keep a very close eye on these pests. If you see populations beginning to climb, start some minor treatments. Some pests, like squash vine borers, won’t be obvious until they have already done a lot of damage.
  • Did you space the plants properly? Cucumbers need lots of room to grow, as they are very fast growing vines. They should be at least 18″ apart, but 36″ apart is great for maximizing your harvest from each plant. Crowded plants are forced to compete for sunlight, food, water, and root space.
  • Are you growing cucumbers during the correct season? Cucumbers do not like the cold, and extremely dry and hot weather in warm growing zones can severely stress the plants. Depending on your growing zone, plan to keep your cucumbers in partial shade in extremely arid, sun baked regions, while keeping them inside of a green house during the colder days of early spring or late fall.

Small Fixes to Help with Failure to Thrive in Cucumbers

If the plants are simply suffering from a bit of neglect, try these little tricks to perk them up quickly! If the plants are too close together, thin out the weakest, smallest plants. Place a soaker hose in the bed, and turn it on every morning to give the plants plenty of water during the dog days of summer, or during the seedling stage of growth. As long as you are not in a drought and the plants are strong with an established root system, watering needs go down to one inch per week. More if the soil is drying out faster. Add some 10-10-10 fertilizer if your cucumbers have not been fed, or if you planted in poor soil without amendments. If the sun is too harsh, shade them a bit; if seedlings are struggling with the cold, try placing a gallon jug, bottom cut off, over the seedlings at night time to help preserve heat. Place small spider glue traps by plants to sample the the insects that are lingering nearby, just in case you have pests that might be hiding.

Watching for Pest Damage in Cucumbers

Before you get upset… know that all of these pests CAN be controlled with neem oil! Isn’t that amazing? A safe alternative to traditional pesticides, and it’s a kill all! Anyways, there are a few pests to watch for; different areas will have different pests that come out in droves. For us, we have to worry about squash bugs, vine borers, and spider mites… as well as the occasional slug. The rest of them? We haven’t had an issue with! Keep an eye out for the following pests:

  • Spider Mites: The spider mite will appear as a teeny tiny yellow or orange dot and tend to appear by the hundreds or thousands (and colors can vary even further, we see orange ones). They are so small that they feed on individual plant cells. Generally, by the time you notice them they are doing some SERIOUS damage to your plants. Or, you might notice their hallmark giveaway: the dense, small webbing on leaves or the end of the branch. The whole plant may begin to wilt and yellow, looking extremely sickly. Batter the plant with a spray of water to knock them off, and apply a spray of neem oil OR a dusting of diatomaceous earth every 2 to 4 days. You could use both for double the protection. Ensure that you dust or spray the underside of leaves as well, in order to help kill eggs before hatching. after 2 weeks, the life cycle should be broken and there should be little trace of them left.

  • Squash bug eggs resting on the underside of a leaf. By Bdm25, via Wikimedia Commons

    Squash Bugs: These guys can be both hard and easy to treat. They are large and easy to spot; adults, nymphs, and eggs too. They like to hide though! They may hide in branch joints, under the cucurbit leaves, or under debris in the bed. The leaves will show yellowing and wilting as they breed; they congregate in large masses, so generally leaves knock off one by one as they spread. For groups of nymphs or adults on leaves, sweep them off with a spoon into a jar of soapy water. For reddish eggs under the leaves, in groups of a dozen or so against the veins of the leaf, do the same. Or, use duct tape to effectively “wax” the eggs off the leaf! Just be careful and avoid damaging the leaf itself. Lay a brick at the base of the plant at night, and squash the hiding adults with your shoe. Their desire to hide makes killing them by hand easy; and with only 1 generation breeding per year, they are easy to control if you stay on top of them! Again, neem oil is an effective spray, and diatomaceous earth will kill nymphs.

  • Adult Squash Vine Borer Moth. By Judy Gallagher, via Wikimedia Commons

    Squash Vine Borers: These are some of the worst pests! They hatch as eggs on the main stem, then burrow inside of the stem. They bore through the main artery of the plant and gorge on it until it’s time for metamorphosis, when they transform into a breeding adult moth. This damage can kill a plant before you know what is going on! While neem oil can be effective, it will only treat eggs that are on the outside as they hatch. It will not affect the larvae who have bored inside. But, Bacillus thuringiensis is here to come to the rescue! A simple syringe and several injections (2 or 3 per plant) will kill existing borer larvae. This bacteria is dangerous for many larvae and caterpillars, and it’s 100% safe and harmless for humans. Inject plants weekly; this will prevent the problem before it starts, and treat infected plants. To keep an eye out for breeding adults as they take flight and breed, place a yellow pan of water in your squash garden. This attracts them and drowns them. When they begin showing up, ensure that you are sticking to a rigorous borer management program… you will see very few issues out of them!

  • life cycle of pickle worm and adult moth.

    Pickle Worms: These insects are incredibly devastating. They attack all parts of the plant, including the fruit. Once fruit is infested, it is inedible. The adults, moths, are active at night; making it harder to identify them during the day. They attack many different cucurbits such as cucumbers, squash, melons, pumpkins, and more. The fruit may have frass on it, but many times infected fruit goes undetected. They are more of a problem in warmer gardening zones, and tend to overwinter in warm climates; they cannot survive a cold winter. If you are in zone 7a or under, like myself, you might not encounter them. Yet again though, Bacillus thuringiensis comes to the rescue! The worms will be killed by this bacteria, and it should be consistently applied with an aggressive schedule. While you might lose current fruits to the pickle worms, future flowers and fruits should be spared with proper pest management. Apply a dusting of diatomaceous earth for the worms who escape death by Bacillus thuringiensis. 

  • Cucumber Beetles: The cucumber beetle loves to play dirty; it will go beneath the soil, within cracks, and feed on the young seedlings from below. Cucumber beetles can ravage entire cucumber plants quickly, even spreading bacterial wilt, helping to decimate crops no matter how large they are. The immature larvae will feed on root systems, as well. Try starting seeds THEN transplanting them to the garden bed once the seedlings begin to get larger and strong. This gives them a fighting chance. Use wilt resistant strains of cucumbers, and utilize neem oil extract to help kill off the infestation. Pyrethrin, a pesticide derived from mums, is also highly effective against the nervous system of cucumber beetles. Keep your guard up against this pest, as bacterial wilt cannot be stopped once the plant is infected.

  • Squash Beetles: This lady beetle is the only one that is actually a pest for gardens, as much of a shocker as that is!

    The Squash Beetle feasts upon the leaves of your cucumbers, while other lady beetles are busy eating the aphids that are harming your garden. Again, neem oil and pyrethrin are wonderfully effective against these beetles. Ensure that beds are thoroughly cleaned and that no cucurbits are planted in the same space for the following year or two, as these beetles overwinter in debris within the bed.


  • Melon Aphids: As you know, aphids can be a true pain. This particular infestation could signal that something is wrong in your area; as there are many natural predators for these aphids. Spray plants heavily with soapy water to knock the aphids off, then rinse them. Release some natural predators, such as predatory aphids or lady bugs. If there is a nearby commercial farm, it is not unlikely that their pesticide program is having a detrimental effect on the beneficial predatory bugs in your area. Try to use other organic and natural pesticides as well, such as diatomaceous earth or neem oil. You could also use insecticidal soaps or pyrethrin as well!

Common Diseases and Fungal Infections to Watch for In Cucumber Vines

Blossom End Rot, on a Tomato. By Nnoddy, via Wikimedia Commons

If you cannot find evidence of pests, or if you have treated for pests and the problem is still occurring, you might have an infection at hand. Viral, fungal, and bacterial diseases all present themselves in cucumbers. Planting certified disease free seeds will help to keep some of these at bay, as long as local pests don’t bring them in and your soil is free of the diseases, or fungi at hand. Here are some of the most common ones to watch for:

  • Bacterial Wilt: Bacterial wilt is a death sentence for cucumber vines. Once cucumber beetles bite the vine and transmit Erwinia tracheiphila, the bacterium breeds and kills the entire plant. At first, the leaves will wilt; then the entire plant dies rather quickly. This disease can only be prevented, not treated, meaning cucumber beetles must be kept under control.

  • Blossom End Rot: Blossom end rot can be a real bummer when you’re waiting on the big harvest. It occurs when there is too little calcium in the soil, and the ends of the fruits turn a dark brown. Since the fruit forms behind the blossom, it is called “blossom end rot”. This makes it easy to identify for new homesteaders and gardeners. Amending the soil with calcium should help to prevent this issue in the future.

  • Powdery Mildew: Powdery Mildew affects many different types of plants, so it is very likely that you have come across it before. The surface of the leaves appear dusty, with a gray coating. This fungal infection, caused by Erysiphe cichoracearum and Sphaerotheca fuliginea, tends to run rampant during hot, humid weather when rain is sparse. The dog days of summer come to mind! Simply washing the plant off with the hose can help with existing powdery mildew. Milk is also another intriguing weapon, as for some reason, one part milk to two parts water seems to eliminate the problem! A mix of 2 or 3 tablespoons of apple cider vinegar mixed with a gallon of water is effective, as well. Vinegar is very effective against fungal infections, but it can harm foliage if the concentration is too strong.

  • Downy Leaf Mildew: If you notice small yellow sores on your cucumber vine’s leaves, keep an eye on them. Downy leaf mildew (Pseudoperonospora cubensis) ulcers will spread and darken to a shade of brown, swallowing one another as the fungal infection progresses. Eventually, the entire leaf is consumed, wilts, and dies. While fruit might not be affected, the plants will slow in growth, become stunted, and produce very poorly, if at all. To control this disease, clean the garden well before overwintering, and keep plants dry. This disease requires cool, wet conditions to spread- so as summer comes knocking, it will retreat. While it cannot effectively be treated with a chemical or home remedy, you can prevent it with some chemicals.

  • Cucumber Mosaic Virus: This is another serious disease that cannot be treated. To prevent CMV, plant resistant cucumber varieties. Pests will spread this disease between vines, so you must keep the pests controlled if cucumber mosaic virus is a common problem in your area. You might find mottled, light green leaves on stunted plants, as well as oddly disfigured and wart covered fruits.

How to Get the Biggest Yield from Your Cucumbers: Cucumber Growing Tips

Aside from keeping your cucumbers well cared for through proper watering, feeding, soil amending, pest management, disease management, and spacing, there are a few extra tricks you can use to increase your yields. See how well you can boost yields using these tricks!

  • Vertical Gardening with Trellises: Cucumbers are vines, and will grow upwards by nature. Not only does this keep vines neat and off the ground, it prevents tangling and reduces competition between plants. The cucumbers are able to grow long and straight, out of the reach of some pests like slugs and overly wet conditions. It also prevents moisture build up on vines, helping to solve a lot of fungal issues before they take hold.
  • Using Compost Tea: Every now and then, try harvesting some compost tea from your compost pile and treating your cucumbers to a delightful drink. This will give them a nutritional boost, helping them to produce more quickly, more often.
  • Bring On the Bees: Try planting clover in the fall, very close to where your garden will be. Come spring, the bees will be drawn to where your garden is, already! They know there is an existing source of food early in the season. This way, your cucumbers (and the rest of your garden) will have an army of pollinators just waiting for those blooms to open. Without high rates of pollination, fewer fruits form.
  • Pick, Pick Pick: Whatever you do, don’t wait for fruits to get “big.” Harvest them at the smallest size that you can! The quicker you pick them, the quicker the vine sets forth new blooms. In addition, the plant does not have to waste energy maintaining those bigger fruits for longer. Smaller fruits tend to be sweeter and juicer, so why not pick them while the pickin’s good?
  • Staggering Plantings: Instead of starting your cucumber plants all at once, try to stagger them by a week at a time. Plant 6 different sets of cucumbers over a 6 week period; try planting 2 to 6 plants per week. This will give you a long lasting, explosive cucumber harvest.