Common Lupin Problems (& How To Fix Them!)

Lupins are a beloved flower on these shores and a staple of gardens up and down the country. But what do you do when things go wrong, and your lupins start suffering from unknown pests or diseases?

Well, as it happens, I love growing lupins and have built up a lot of experience over decades of carefully nurturing these plants. So let me help you and get to the bottom of your lupin problem, whatever it is!

My Lupins Are Being Eaten!

Something is eating your lupins, but you are not yet sure exactly what it is. Here are some more common pests you will find nibbling on your lupins.

Once you know what's eating your plant, then you know how to fix it!

Slugs and Snails

I will start with the most common pest for lupins, the classic slug and/or snail.

Slugs and snails love lupins, and if the plant is young, or just starting to grow again in spring then they can even do enough damage to wipe the lupin out!

Here is a lupin straight from my garden, and as you can see something has been munching on it.

The giveaway as to what was eating this plant is right in the middle of the photo. If you look closely, you can see a slimy trail all over one of the leaves.

This is the most obvious sign you will see and tells you that slugs and snails have been feasting on your precious lupins.

How to get rid of slugs and snails

So if slugs are your pest, how do you keep them away from your lupins?

Well, there are a few options open to you, and your choice will depend on whether you garden organically or if you have small children or pets in your garden.

Slug Pellets

if you want the best way to kill slugs and don't care about being organic, then just put some slug pellets down around your lupins.

If you have pets or small children in the garden, I would advise against this as the little blue pellets can be particularly attractive to small children, and they are a poison after all, so this could be problematic.

Nematodes

Nematodes are a type of microscopic roundworm that is found naturally in UK soils. When they enter the host's body, in our case slugs, snails and release bacteria. This kills the slug, and the nematode then digests the slug's body.

They also change the slug's behaviour which causes them to die underground, so you don't have tonnes of dead slugs lying around on the soil's surface.

Nematodes are a biological way of killing off slugs instead of a chemical way.

As I said, they are naturally found in your soil. What you are doing with this product is just significantly increasing the number in your soil for a short duration.

If the nematodes are successful and find slugs to eat, they will often reproduce and you will have an ongoing slug-eating frenzy in your garden.

Beer Traps

A beer trap is an organic way of getting rid of slugs. Essentially you set up a cup or saucer buried into the soil with the top of it level with your soil.

You then fill the bottom of the cup with beer. The idea is that the slugs are attracted to the beer and fall into your trap. They then can't get out and either drown or are removed by yourself from the cup.

While the idea sounds really good on paper I have often found the ineffective and slugs just seem to ignore them.

Aphids

Lupin aphids can completely take over a plant quickly. As you can see in the photo below, they can completely cover the stem of a lupin plant.

Lupin aphids don't "eat" the plant per se, but this does not mean that they are not dangerous to the plant.

They suck the sap out of the plant, and if there is a large enough infestation they will do enough damage to cause the lupin to wilt and sometimes even die.

You want to try and take steps to control aphids as soon as you see a few on your lupin as they can take over really quickly.

How to get rid of lupin aphids

So you've found aphids on your lupins. How do you kill them off? I have a few ideas for you below, some organic and some not.

Bug Spray

Probably the most common option and also the most effective. You can get organic bug sprays, but they are never as good as non-organic ones.

If you just want to kill the aphids and save your lupins, then I recommend the miracle grow bug spray. I have used this spray myself after being recommended it by another gardener, and it does work wonders.

Rose clear, made by the same company can also work well on lupin aphids so if you have some lying around then give it a try.

Homemade Sprays

There are lots of old wives' tales when it comes to homemade aphid sprays which may be worth trying out, but I must say I have not used them myself as they never seem to work.

Garlic spray, mix some crushed garlic in a spray bottle with plenty of water, spray directly onto the aphids and wait around an hour before spraying off with regular water to rinse the flowers.

Soap spray is also meant to work well on lupin aphids. Mix some washing-up soap with water before applying and rinsing off as above.

Knock them off

Aphids don't like being knocked off lupins and can struggle to get back up onto the plant. If you regularly knock them off the plant and squash a few, then this can help to keep the infestation in check and is about as organic as gardening gets.

Ladybirds

Another pest control solution like the nematode for slugs. Ladybirds love feasting on aphids, and a single ladybird can eat thousands of them in a lifetime.

So if you have lots of aphids then you don't have enough ladybirds in your garden, but how can you fix this?

These are live ladybirds in their larvae form. You can apply them directly to the plant, where they will immediately get to work munching on aphids. When old enough, they will transform into ladybirds and continue munching on aphids. Win-win!

White Fly

Little white bugs on your lupins are most probably whitefly. These tiny little flies lay eggs on the underside of the leaves of a lupin plant.

They don't only nest on lupins but can actually be found on lots of different plants and are a common greenhouse pest.

While in their larvae form they will feast on the leaves of your lupins and can cause considerable damage.

How to get rid of whitefly

So if you have found that you have a whitefly problem, you will want to get to work getting rid of them before they can cause too much damage.

Below I will give you some of my best methods for getting rid of them.

Ladybirds

Just like aphids ladybirds love feasting on whitefly, and a single ladybird can eat thousands of them in a lifetime. So if you have lots of whiteflies, then you don't have enough ladybirds in your garden, but how can you fix this?

Hose them off

You can quite often blast whitefly off your lupin's leaves by using a hose. If doing this, it would also be advisable to remove the leaves with a heavier infestation in order to remove the larvae and prevent them from reproducing.

Doing this regularly can help keep whitefly infestations under control, but it is likely to kill them off completely.

Bug Spray

Again just like the aphids listed above a bug spray like bug clear ultra will work really well here.

Why are my lupins drooping?

Let's look at some of the more common reasons I know that can explain drooping lupins.

Pest attack

Lupin aphids are the most common pest that can cause drooping in your lupins.

Poor roots

If your lupin has been recently bought from the garden centre, then it may have a poor root structure.

Lupins like to grow a large tap root, but garden centre lupins are often forced. This makes them grow quicker and look better in the store, but they are often not healthy plants.

They tend to end up in a situation where they can have too much foliage, and it is tough for the roots to support the plant.

If this is your issue, then all you can really do is wait and allow the plant time to establish itself and develop its root structure.

Too hot

Lupins are well suited to growing conditions in the UK which is normally pretty cold and wet, let's be honest.

What this does mean though is that if we get an extended really hot spell, then lupins can sometimes suffer.

There isn't much you can really do here apart from keeping your plant well-watered and waiting for the hot weather to pass, which normally happens sooner rather than later.

Too wet

Most soil conditions are fine for lupins, but the one thing they really don't like is wet roots. If your soil is waterlogged, then this could be the reason for a dropping lupin.

You have two choices if this is your issue. You can either move the lupin to another area in the garden or improve the soil drainage around the lupin.

If you choose to improve the soil try to add sand and maybe even a bit of gravel to your soil mix, this will help to improve the drainage.

If the lupins are in a particularly wet spot, you might have to take more serious action, like digging a french drain.

Seasonality

With the changing of seasons comes problems for lupins. While being a perennial plant, they do die off every winter before bouncing back to life come the following spring.

So if it is mid-Autumn or we have had a very cold autumn, then this completely natural reason could be why your lupins are starting to look a little sad.

Virus and Disease

There are lots of different diseases that can affect lupins, and probably more than I could ever list.

In truth, there is not a lot you can do about most of these problems, and sometimes, the best solution is to remove the affected plant and destroy it.

Brown Spots

Lupin anthracnose is a fungal disease that is the most common disease in Lupins.

Brown areas on the leaves or stems of your lupin are a sign of this disease. It is a spore-born disease that lives in the soil without a real cure.

The leaves will also turn, shrivel and corkscrew as they turn brown.

My advice is to avoid planting any lupins in this same area of the garden again for several years, which should give the spores time to die off.

You can sometimes save the plant if you spot it early enough by removing any affected leaves as soon as they appear. Dispose of the leaves straight away (not in the compost heap!)

After a few years have passed, it should be safe to plant lupins in this location again.

Powdery Mildew

The leaves of a lupin will have a powdery growth on them.

This is often white or a pale grey but can sometimes be black. This one is usually a simple cure as it is often caused by improper watering and insufficient airflow.

Remove the affected leaves from the plant and then try to water them at the base of the plant going forward and avoid watering the leaves.

Aphid Viruses

As well as sucking the sap out of lupins and damaging them, aphids can also transfer viruses to lupin plants.

A lupin affected by an aphid virus will usually have strange, stunted growth, which is often twisted downwards.

There really isn't any cure, so you just need to remove the plant and destroy it, don't put it on your compost heap in case the virus spreads in your compost and affects other plants.