Lupines typically die due to Overwatering, underwatering, poor drainage leading to root rot, and disturbance of the taproot during transplanting. Diseases like fungal infections or viruses can also lead to decline. Intense sun, extreme heat, or high winds may damage foliage. Finally, pests like aphids, slugs, or root-gnawing critters may infest plants.
Ensuring proper soil moisture, drainage, watering, disease treatment, pest control, and appropriate site conditions will help prevent lupine die off and keep them thriving.
Lupins are a favorite of cottage gardeners. Lupin plants are nitrogen fixers and are beneficial to your garden in many ways.
Lupin leaves turning brown?
Lupin leaves turning brown is typically a sign of stress. Underwatering causes leaves to dry out and brown. Overwatering or poor drainage can lead to root rot and browning foliage. Hot, dry weather scorches leaves. Wind damage can also brown leaves and stems.
Diseases like fungal infections may spread. Ensure lupines get 1-2 inches of water weekly, improve drainage in heavy soil, provide some shade in intense sun areas, and treat any pathogens. Addressing the underlying issue will help reverse browning leaves and restore lupine health.
Root rot and brown leaf spot disease
Overwatering is the main reason why roots get rotten in Lupins. Root rot and brown leaf spot diseases are caused by a fungus called Pleiochaeta setosa.
Overwatering creates waterlogged conditions around your Lupins. Waterlogged conditions favor the growth of root rot-causing fungus.
Symptoms
The fungal infection can be first seen on the leaves of Lupins. Leaves become wilted and brown spots are formed on the leaves, stems, and pods.
These brown spots enlarge with time and form a network of dark spots. In case of a severe infection, infected leaves fall off.
Severely infected seed pods transfer the disease to the seeds. Other types of root rot fungi may cause brown spots at the base of the stem.
Brown leaf spot/Root rot control in Lupins
- Rotating the crops is quite beneficial in controlling these diseases in Lupins.
- Avoid splashing water onto the foliage.
- Apply Procymidone or Iprodione based seed-dressing fungicides to reduce the risk of transferring the disease to seeds.
- Get disease-resistant cultivars if possible.
Lupin Anthracnose
Anthracnose is a fungal disease which can prove fatal to the plant if left untreated. Anthracnose spreads to healthy plants via water splashes.
A number of brown lesions form on the leaves and petioles of Lupins. If a lot of brown lesions form on the petiole, it droops.
Control Anthracnose in Lupins
- Using disease-resistant cultivars is the ideal way to prevent Anthracnose.
- Do not wet the leaves of your Lupins when watering the plants.
- Cut off the infected leaves with pruning shears to prevent a large-scale infection. Spray the infected plant with a copper-based fungicide for the best results.
Lupin leaves curling
Curled lupine leaves usually indicate environmental stress. Insufficient water results in leaves curling and wilting as the plant conserves moisture. Too much moisture can also cause leaves to curl. Intense sun and hot temperatures cause foliage to curl to minimize water loss.
Pest or disease problems can lead to distorted growth. Ensure lupines receive adequate water for your climate, provide some shade if too hot, and treat any pathogens or infestations present. Alleviating the source of stress will allow leaves to return to normal flat shape.
Aphid infestation in Lupins
Three types of aphids infest Lupin plants. Cowpea aphids(black), Greenfly (waxy green), and the Bluegreen aphids.
Aphids are carried to the host plants by ants, so try to control ants around susceptible plants. All three types of aphids cause the same damage to your Lupins.
Aphids cling to the stems and leaves of Lupins and suck out the plant sap. They excrete honeydew which attracts a wide variety of fungi.
Aphid infestation distorts the stems and leaves of Lupins. A severe aphid infestation causes loss of produce. In addition to this aphids transmit a variety of viruses.
Control Aphids in Lupins
- Hang yellow, sticky cards around plants to identify an infestation early.
- Spray off the aphids with a garden hose as soon as you identify them.
- Spray neem oil weekly until you get rid of aphids completely.
- Get an aphicide that doesn’t kill beneficial insects and only gets rid of pesky aphids. Do this only in the case of a severe aphid infestation.
Whiteflies infestation in Lupins
Whitefly infestation also causes leaf curling in Lupins. You’ll find whiteflies on the undersides of Lupin leaves.
Whiteflies can’t be controlled easily so you better treat them as soon as you see them. Wash them off using a water spray from a garden hose.
Whiteflies feed on Lupins and excrete a sticky material called Honeydew. Honeydew attracts a variety of fungi.
Control Whiteflies in Lupins
- Hang yellow, sticky cards around your Lupins to identify their presence earlier.
- Cut off the infested leaves to control their spread.
- Spray Safer’s Insecticidal soap if the whitefly infestation is severe. Spray it once a week for two or three weeks for the best results.
Lupin leaves turning red
Lupin leaves turn red when you feed the plant with a lot of manure. Lupins don’t like to be fed too much manure. If they get a lot of nutrients the chlorophyll in leaves is replaced by red pigment.
If there’s a lot of manure around your Lupin plant get rid of it. Replace the enriched soil with poorer soil. If the plant has been planted recently move it to a different place.
Cut off the leaves that are turning red/yellow with a pair of sterilizer pruning shears. The plants should come back fine.
Why are my Lupin seedlings going yellow?
Yellowing lupine seedlings often points to overwatering issues. Too much moisture can lead to root rot, causing leaves to go chlorotic and yellow.
Soil that doesn’t drain well and retains excessive water is a common culprit. Allow soil to partially dry out between waterings. Amend heavy soils with compost to improve drainage.
Ensure pots and trays have drainage holes. Cut back on watering if soil is soggy. Protecting roots from excess saturation will prevent yellowing and encourage healthy seedling growth.
Iron Chlorosis in Lupins
Lupins turn yellow when the plant can’t absorb an adequate amount of Iron from the soil. This can happen due to various reasons like, pH imbalance or poor soil.
Identify Iron chlorosis early and try to treat it before your Lupins die. Iron chlorosis causes abscesses in the leaves of Lupins.
- A good cultural control method is to lower the phosphorus in the soil. Use fertilizer with lower Phosphorus content.
- You can fix Iron chlorosis in Lupins by using a High-Yield Iron Plus Soil Acidifier.
Overwatering
We already discussed what overwatering can do to Lupins. Yellowing of the foliage is the primary sign of root rot in Lupins.
Check the soil with your fingers and water the Lupins only when necessary. Get a soil moisture meter if needed. Make sure the soil drains excess water well.
Underwatering
Underwatering can turn leaves yellow too. Underwatered plants’ leaves turn yellow and dry, unlike overwatered plants whose leaves turn yellow but droopy.
Water your Lupins if the soil is dry up to two inches. Check the soil with your fingers if you want but do not let the soil go bone dry.
Lupin dying after transplant
The lupin plant dies after transplant due to transplant shock. However, they can be tricky to transplant. Lupins have a long taproot that when disturbed, makes it hard for the plant to establish itself in a new location.
The key is proper soil preparation before transplanting. Make sure the new area has loose, sandy, fast-draining soil. Dig the hole at least twice as deep and wide as the root ball.
Backfill with compost to encourage new root growth. Water thoroughly after transplant and provide partial shade for a few days.
Proper care when transplanting lupins will give them the best chance to settle in and thrive. With some extra attention, their gorgeous blooms will grace your garden.
Why is my Lupin drooping?
Overwatering and underwatering are common causes of lupin drooping as moisture levels affect the roots. Hot, dry weather can also cause temporary wilting until turgor pressure recovers.
Several issues can cause lupin leaves and stems to droop, wilt, or appear limp. Overwatering is a common culprit, as too much moisture suffocates the roots and leads to decline.
Underwatering can also cause drooping as the plant becomes stressed from lack of water. Hot, dry weather or winds may cause temporary wilting until the lupin can recover turgor pressure.
Root rot due to poor drainage or disease will impair the roots’ ability to take up water. Physical damage to stems and leaves from pests or injury can disrupt water transport.
Finally, transplant stress if not properly cared for can cause temporary drooping. Checking soil moisture, amending drainage, using mulch, and providing ample water until the lupin establishes can help prevent and alleviate sagging stems and leaves. Target the specific cause and lupins will perk back up!
Why do Lupins get Mildew?
Lupins get mildew when they are infected with fungi. There are two types of mildew diseases that can affect Lupin plants. Lupin leaves turning white is mainly due to Powdery Mildew.
Powdery mildew in Lupins
A powdery layer forms on the Lupin leaves. This powdery layer is usually white/gray in color. Small black dots are seen later on the infected leaves.
Cut off the infected Lupin leaves with a pair of pruning shears. Dispose of the infected leaves carefully, do not leave them in the garden.
Powdery mildew spreads via water splashes so avoid wetting the leaves when you water your Lupins. Respond as soon as you see the symptoms to revive your plant.
How do you treat Powdery Mildew on lupins?
- Spray a mixture of milk and water(1:9) on the affected leaves on a warm day.
- Mix a tablespoon of baking soda in 8 pints of water. Spray this on the affected leaves.
Downy Mildew in Lupins
Downy mildew is a type of fungal disease whose symptoms are first seen on the undersides of Lupin leaves. Downy mildew is usually seen in spring.
Infected leaves of Lupins turn purple and curl down. A whitish or grayish outgrowth can be seen on the undersides of the leaves.
Just like powdery mildew, downy mildew spreads via water splashes too. So avoid watering the plant from top-down.
Tip: Choose resistant varieties if possible.
Treat Downy mildew in Lupins
- Prune the infected Lupin plant to improve air circulation.
- If you see this disease every year, spray copper fungicide on the plant two/three weeks before the wet season.
- Mix 3/4 tsp. ‘Organocide by Plant Doctor’ in a gallon of water. Spray this on the infected plant to get rid of this disease.
Do Lupins die back?
Yes, lupines are herbaceous perennials that die back each winter. Their foliage and stems grow from spring until fall when cooler weather arrives. Once freezing temperatures hit, the above ground parts of lupines will turn brown and shrivel as the plant goes dormant.
But the roots will survive underground through winter. Come spring, new shoots will emerge from the established roots to start the growth cycle again.
This seasonal die back of top growth is natural for these perennials. The roots living on allows lupines to return year after year.
Do Lupins die back in Summer?
Lupins die back in summer typically due to overwatering, underwatering, extreme heat, root rot, and pest damage. The long taproot may also be disturbed from transplanting.
Lupines dying back in summer is not normal growth. Their foliage should remain healthy through summer into fall. Summer decline indicates an underlying issue.
Ensure proper soil drainage and moisture, mulch to retain water, provide some shade if too hot, and treat any diseases or pests. With good care, lupines should flourish through summer. Dying back earlier likely signals a problem needing attention.
What insects eat Lupin leaves?
Snugs and snails love to munch on Lupin leaves. Slugs and snails not only devour leaves, they also munch on flowerheads.
Some species of slugs can be very destructive. Do not let the slug infestation go out of control as they can damage the produce to a great extent.
Get rid of Snails in Lupins
- Crush two garlic bulbs and add them to two pints of water. Take these into a pan and boil for 20 minutes, let it cool.
- To make the spray mix 2 teaspoons of this solution in a gallon of water.
- Spray the plant and the surrounding soil once a week to deter slugs and snails. Do not spray this solution on the blossoms.
Why are my Lupins not flowering?
Lupins fail to flower when they don’t get adequate sunlight. Sunlight is the reason if Lupins look healthy but do not blossom.
Lupins love full-sunlight or partial-shade conditions. Remember that Lupins bloom from late spring to early summer.
I’d advise you to plant your Lupins so that they get partial sun. Cut off the neighboring plants to allow some sunlight in.
This usually happens in the early summer so keep an eye on your Lupins during this season. Cut your Lupins back after flowering to induce a second round of blossoms.
Do Lupins die back in summer?
Yes, Lupins die back in summer just after the blossom season. Flowers die from the bottom to towards the tip.
Cut back your Lupins hard when you see that the 2/3rds of the flowers are spent/brown. Doing this you can ensure a good blossom the next season.
Deadheading your Lupins is a great way to maintain the plant’s resources. A second season of flowering can be seen later in the summer if you’re lucky.
Do Lupins come back every year?
Yes, lupines are herbaceous perennials that will come back every year once established. In winter, their foliage dies back after freezing temps but the roots survive underground.
When spring arrives, new growth emerges from these living roots. This cycle repeats annually. Lupines may take 2-3 years to fully settle in before blooming reliably.
With proper site selection, care, and overwintering protection, their beautiful flowers will return and enhance your garden year after year. The roots allow these perennials to keep coming back.
Why did my Lupins not come back?
If Lupins fail to re-emerge in spring, the roots likely did not survive winter. Insufficient mulching and extreme cold may damage roots. Poor drainage or too much moisture causing rot is another culprit.
Pests like voles gnawing on roots destroys overwintering parts. Improper planting depth could also lead to decline. Choose appropriate sites, plant at correct depth, provide winter mulch, ensure adequate drainage, and protect from pests.
Taking steps to maintain healthy roots through winter gives lupines the best chance of returning year after year.
Happy Gardening 🙂