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Cardinal Climber is an annual vine which produces numerous red flowers and can grow 20′ or more in full sun. In my experience, this is the ultimate plant for reliably attracting humming birds to your yard/garden for nearly the full season. Every morning we can see different humming birds visit this plant about every 10-30 minutes as well as sporadically throughout the day. It is great for shooting up a mailbox, pole, or even bridging a gap up your house. Down below I will have some pictures of an idea my wife that was really clever. She ran some fishing line from a concrete flower pot on the ground up to a exterior garage light. And this vine dutifully climbed that fishing line making a really cool flower display in-between our garage doors.

Although not a native plant, it isn’t invasive in cold climates as the seeds tend to die / go sterile when exposed to frost. It is incredibly easy to grow from seed and once the soil and air temperatures warm up it will have a very fast growth rate (starting around May in Zone 6/7).

Cardinal Climber Facts

A hybrid invented in 1897 by a man named Logan Sloter from Columbus Ohio
- He hand pollinated the hybrid cross between cypress vine and red morning glory, which are both native to South and Central America
Typically grows 15-20′ long, producing many red flowers
Cardinal Climber is amazing for attracting hummingbirds
Is an annual, and the seeds will not survive a frost
The seeds of Cardinal Climber are very toxic to humans and pets
Can be invasive and weedy in warm climates
The Scientific Name of Cardinal Climber is Ipomoea sloteri

Physical Description

This is a vine, and it will make multiple shoots sprawling in all directions, looking for places to grab and climb. It does this to try to get sunlight.

Stalk / Stem

The stalk of Cardinal climber is quite stout for its size. The diameter of the stalk will generally be 1/4″ (~6 mm), and the primary shoots can grow 15-20′ long. There will be branching of other stalks along the primary stalks, leading to a sprawling vine. If there is nothing for the stalk to grow ‘up’ then it will sprawl on the ground, or trail.

Leaves

The leaves are alternate, with deep sharp lobes. I’ve not noticed any similar leaves that are native to vines in Eastern and Central North America. There are generally about 7-10 lobes, and the overall shape of the leaf is like a triangle. But I also think it somewhat resembles a hand with 10 fingers.

Flower

The flowers are a bright, rich red color. Shaped like a trumpet that is about 1-2″ (25-50 mm) long, by 1/4-1/2″ diameter (6-12 mm). But instead of being round, they are pentagon shaped. The deep throats give hummingbirds an advantage in nectar feeding, as their long beaks make it easier for them to feed on the nectar.

The flower will eventually produce a fruit that turns into a seed capsule. The capsule will have several seeds inside. These seeds are highly toxic – so take care if you have children or pets. You can deadhead the plant, but this would be a labor intensive process since there are so many blooms per plant.

Root

The root of Cardinal climber is a shallow taproot, with numerous other roots attached to the bottom of the taproot. Since the roots are quite shallow, making this plant a great candidate for container gardening.

Growing Conditions for Cardinal Climber

Cardinal Climber vine will thrive in full sun, hot temperatures, and moist well drained soil. This plant will not start growing very fast until temperatures warm up. Because of this, I no longer start seeds indoors, but direct sow them. Even if you get it growing well indoors, it will slow or stop growing outside unless you have hot temperatures. I have found that seeds started outdoors in Spring will catch up to plants started indoors. By doing this, I save myself the extra step of transplanting the vine.

Is it invasive?

The seeds of Cardinal Climber don’t seem to survive winters in cold climates. I believe this is because it is a hybrid of two tropical plants. So, it might just be that if the seeds freeze, they die and won’t germinate. I’ve grown this plant multiple times, and I have never had plants the following Spring. However, if you live in a warm climate – exercise caution. This plant produces a ton of flowers throughout the growing season, and therefore a ton of seeds. You could have many unwanted seedlings if you live in a warm climate.

How to care for Cardinal Climber

Make sure the soil has some fertility. Mix in some compost while planting to ensure it has all the nutrients it will need throughout the growing season. If you aren’t making your own compost yet, see our quick easy guide to start composting by clicking HERE.

Maintenance

Cardinal Climber may, or may not need maintenance depending on where you plant it. And by maintenance, what I am saying is that this plant can get out of hand in certain areas. It will grow on anything it can climb – including other plants. I find it is best to keep this in an area where there is almost no other competition. When I have planted it in flower gardens, I find that I have to often snip of unwanted shoots/runners that are strangling my other plants and stealing their sunlight.

How to Establish Cardinal Climber

This is one of the easiest plants to grow from seed. It germinates really fast if you follow my process below.

How to Grow Cardinal Climber from Seed

Wait until about 1 week after your last frost before sowing. Frost will kill this plant and the seeds.
Put seeds in a dry coffee cup.
Run hot tap water and fill cup about 1″ above the seeds.
Let the seeds soak for 24 hours.
Plant the seeds about 1/4″-1/2″ deep in pots, or directly into the ground.
Keep moist until germination, which usually occurs within a week. I often find that it will occur within 48 hours if the seeds were soaked for 24 hours.
If grown in starter pots, transplant out into final location after the first true leaves (multiple lobes) develop.
Here is a picture of a Cardinal Climber Seedling that just germinated

Purchase Seed

How to Save Seeds from Cardinal Climber

After a bloom has withered a small fruit will form. Once this fruit turns brown, you can collect them by sniping or picking them off the vine. Do this after the pod has dried, but before it breaks open to release it’s seed. Then, just open the capsule to get several seeds.

You can store Cardinal Climber seeds after drying them for about a week in a cool/dry place. Put them in an air-tight container or zip-lock bag. Keep in a cool/dry place, just like when you store most other seeds.

Garden Uses

This plant is best suited to be by itself, or with very few or no other plants that it can climb. We use it on our poles for our retractable patio shade. As these poles are contained in whiskey barrel planters. But in general, Cardinal Climber does what it name implies – it CLIMBS.

Cardinal Climber will look great on a trellis. It would also climb right up a flag pole, but can be so prolific that it might interfere with the raising and lowering of flags. Growing along a fence would be a great place for it, and would be sure to draw in tons of hummingbirds. So I will post a few pictures below and you can see how we currently use it at our home.

Alternatively, this plant can be used as a ground cover. But it will cover other plant. This could result in the shading out and death of plants that don’t go dormant by mid-summer / 4th of July.

Fauna

This plant will bring in the hummingbirds. I set up a video camera one morning not long after dawn. I let the camera run for about 90 minutes, and one plant drew in 11 hummingbirds in that time. So that averages to about 1 hummingbird every 8 minutes. Need I say more? Now, the morning is one of the more active times for hummingbirds (in my experience). But I do see them regularly throughout the day feeding on my plants.