How to Grow & Care for Nelly Moser Clematis (Clematis Lanuginosa)

Last Updated on October 31, 2021 by Phil

The Nelly Moser clematis (Clematis lanuginosa) is a flowering vine that is well known for its beautiful blossoms. Better yet, they bloom twice a year, once in the spring and then in the summer, which doubles the fun.

Just as interestingly, it is the parent of many large flowering clematis varieties including the Clematis jackmanii.

The plant grows up to 10 or 12 feet tall. But, its crowning glory are its large (6 to 8 inch) 8-petaled start shaped flowers that are adorned with white borders.

This makes them instant attractions for any garden, especially when allowed to climb up a vertical spaces which is does so well.

Table of Contents

Nelly Moser Clematis Plant Care

Nelly Moser Clematis Light

The Nelly Moser clematis thrives in full sun (6 or more hours a day). And, like many other clematis varieties, it likes to have its head in the sun and its roots in the shade. Thus, it is a good idea to find a sunny spot where I will receive a good amount of sunlight. But, protect its base with 2 inches of mulch, shallow rooting ground cover or stones to block off the sun’s rays.

However, do keep in mind that it doesn’t do well with too much sun. That is, leaving it all day under harsh direct sunlight is a no-no. This is especially true if you live in a warm area or the summers are brutal.

As such, it is best to give it part shade during the mid afternoon when the sun is most intense. It will also appreciate this during the peak of summertime. Being protected this way will allow it to keep its beautiful colors longer.

Thus, the best spots to keep the plant are in the south, west and east facing sides of your garden. In the first two, make sure to check how much direct sunlight and at what intensity the locations receive during the mid-afternoon. This way, you can set up some kind of shade to keep it protected.

If you don’t have a choice but to keep it in the north or somewhere there isn’t a ton of light, it is important to be creative. One way of doing this is to keep it near a white wall. This will help the light bounce back from the surface to the plant.

Nelly Moser Clematis Temperature & Humidity

The Nelly Moser clematis grows well outdoors in USDA zones 4 to 8. As such, it likes cool to very cold weather between temperatures -30 degrees Fahrenheit to 15 degrees Fahrenheit.

It also means that while it can tolerate some frost, it won’t be able to withstand extreme temperatures. So, at the lower range, you’ll want to provide it with enough much when winter comes around.

But, as you can notice, the thing that it cannot tolerate is warm weather, especially for its roots. As such, it is important to provide it enough shade when the sun gets hot while allowing it to receive ample light (minimum of 6 hours daily).

Watering Nelly Moser Clematis

The Clematis Nelly Moser isn’t a particularly thirsty plant. As long as it receives an inch or water weekly, it will be happy. If you’re an experienced gardener, you’ll have a good idea of how much rainfall there has been recently just by observing.

However, if you don’t like having to keep track of how much rain there’s been in the last 7 days or so manually, I’ve found that getting a rain gauge really helps. It’s a very cheap device. And, it saves you from overwatering your plants, which isn’t a big problem once in a while. But, done regularly, can be disastrous for your garden.

The Clematis lanuginose is particular vulnerable to clematis wilt. And, because it has no cure, is something you really want to avoid. Similarly, too much moisture puts your plant at risk of powdery mildew and other fungal problems, not to mention root rot.

As such, make sure to keep the plant somewhere there is good air circulation. This will help excess moisture on its foliage as well as the soil dry faster.

It is likewise important to keep in mind the plant’s preference for cooler weather. This means you’ll need to water it more during the dry and warmer months. Adding a layer of mulch also help with water retention. But, if you do, make sure to replenish the much every spring.

Soil

Your Nelly Moser clematis likes moist, well-draining soil. It also prefers slightly acidic soil that has a pH or between 5.7 and 6.5. You do not want to go much higher than that because the higher off you go, the more susceptible the plant become to yellowing.

Additionally, rich, fertile soil will also allow it to produce vibrant blooms.

When planting, make sure you dig a big enough hole for the plant. Clematis take up a lot of space on the ground. And, their climbing nature also means you’ll want to set up some kind of structure to support it.

Since the Nelly Moser grows to over 10 feet, a high fence, arbor, trellis, wall, pergola or something similar works well. It is not a good idea to use shorter poles like you would for smaller clematis because the plant will outgrow it.

With this plant, mulch is your friend. Mulch protects it from the sun during warm months. It also helps with water retention. During the winter, you also want to apply a healthy layer of mulch to keep it from too much frost. But, when applying mulch, avoid the crown.

Fertilizing

In addition to rich soil, you want to supplement your Nelly Moser clematis with plant food. Apply a low nitrogen fertilizer once a month during its growing season.

If you live outside of its hardiness zones or prefer keeping it in a container, make sure that the plant has enough drainage. You’ll also want to stay away from overfeeding since it is easier to do so in limited spaces like pots.

You can us a fertilizer with N-P-K ratio of 5-10-10 or 5-10-5. Since clematis are flowering vines whose main attraction are their blossoms, you want to keep the nitrogen (the N) low. This will limit foliage growth and let the plant focus on its blooms. Similarly, you want the second element P, to be higher as this is what promotes flowering.

When growing your clematis Nelly Moser, it is likewise important to be aware of where the other plants and elements in your yard or garden are. I remember a friend whose clematis wouldn’t bloom. And, when they did, they flowers were lackluster.

After a look it was obvious why. The plant was situated against a fence right beside their lawn. Since grass grows on fertilizer that’s nitrogen based, this made their clematis grow more leaves than it did flowers.

So, do keep the plant away from the lawn and other foliage plants that feed on higher nitrogen fertilizer.

Pruning Nelly Moser Clematis

The Nelly Moser clematis doesn’t need a lot of pruning. But, you will want to remove the dead parts after the plant blooms. This includes the brown, dying or brittle sections.

It belongs to pruning group 2, which means you want to prune it after they bloom. This will be between winter or early in the springtime and after the first flush of flowers during summer.

When you trim don’t cut off more than a third off the top. Since the plant grows on old wood, you want to keep that as the foundation. Doing so will optimize flower production.

On the other hand, if you cut it down to the ground or prune it during the fall or springtime, its flowering may be delayed or lessened.

The main goal of pruning for this plant is to keep it neat looking, limit its size and encourage new growth. As such, you don’t need to do be too aggressive or do too much of it.

It is also a good idea to cut the vines back to about 1 to 2 feet while it is young. This will encourage outward growth when it regrows which makes the plant look denser.

Propagation

Clematis lanuginose ‘Nelly Moser’ can be propagated via cuttings and layering. Of the two, semi-hardwood cutting is the more popular method because it is much easier to do.

How to propagate Nelly Moser clematis from Cuttings

To do this, you want to use semi-hardwood cuttings. That is, wood that is still somewhat green (soft) and hasn’t turned into its brown color (hardwood).
Pick a stem that is 4 to 6 inches long. You also want a healthy stem with at least a few leaves on it
Cut if off using a sterilized pair of scissors of shears. Do this just below the leaf node.
Once you have the cutting, your goal is to get it planted into the soil withing the next 12 hours.
Remove the lower leaves and dip the end into rooting hormone power.
Insert the cuttings into a small container that contains well-draining potting mix. You can use sand or perlite to improve its drainage if needed.
Water the soil and keep it consistently moist.

Nelly Moser Clematis Transplanting & Repotting

Planting or transplanting your Nelly Moser clematis requires some planning ahead of time. While the process isn’t difficult, there are a few things you’ll want to do first because of its preferred living conditions.

Make sure that the location you choose gets at least 6 hours of sunlight. But, do keep it away during the most intense times of the day. The easiest way to do this is to have some kind of shade come over it during mid afternoon if you live in a warmer region.
If you live outside of the plant’s hardiness zones, you’ll want to get a good sized container. Make sure that the pot has holes at the bottom for drainage purposes.
Ideally, you want soil to be fertile, slightly acidic and well draining (with a little bit of water retention ability). You don’t want overly heavy soil like clay. Nor do you want sand-like soil. Use compost to improve soil quality if needed.
If you’re growing it in a container, make sure you use a high quality potting mix that’s loose enough to allow air and water to pass through. If it doesn’t drain well, add perlite to improve this.
The clematis Nelly Moser is a climber. As such, it is a good idea to plant it beside a vertical space or structure. A wall, fence, arbor, trellis or something similar works great.

Once you’re ready, dig a large enough hole to fit the plant. You want to make the hole deep enough to let the crown be about 2 to 3 inches under the soil surface.

This will help keep the roots cool. It will likewise allow the plant to recover from clematis wilt better in case that happens.

If your soil is heavy, you can dig deeper to give you enough space to add compost or sand at the bottom. The former will help improve soil quality and drainage, whereas the sand allows moisture to drain faster.

When you’re done, backfill the hole and water the soil.

Toxicity

Keep kids and pets away from your Clematis lanuginose ‘Nelly Moser’. The plant is toxic to people and animals. So, it is important not the let little children, dogs, cats and horses near it.

Ingesting any part of the plant causes a wide range of problems including irritation, swelling, vomiting, dizziness and convulsions to name a few.

Also, do wear gloves when pruning or propagating the plant. It can cause skin irritation. Although, this doesn’t seem to affect everyone.

Pests and Diseases

Being cautious with moisture is very important with your Nelly Moser clematis. That’s because it is susceptible to Clematis wilt which will cause parts of your plant to turn black and its stem to wilt. More Importantly, it can be deadly.

Additionally, other moisture related issues it faces include powdery mildew and leap spots.

As such, make sure not to overwater the plant. Also, don’t water over it which will drench its leaves. instead, water directly on the soil.

When it coms to pests, its most common issues include spider mites, scale, aphids and earwigs. Thus, do regularly inspect the plant and treat it as soon as possible.