Ageratum Plant Care & Growing Guide

The ageratum plant offers a beautiful splash of color to your garden, but it can be challenging to grow. 

Most of these plants are actually hybrids, and they don’t take up much space. You’ll find that the effort you put into growing this plant will be well worth it in the end.

Ageratum Plant Care & Growing Guide

1. Light Requirement

These plants thrive when they are given full, direct sunlight on a daily basis. While you can keep them in the shade, they should still be getting a good amount of sun. If you live in a region where temperatures can get very high, a semi-shady spot is probably best.

 If you keep the plant indoors, it should be placed near a window that receives direct sunlight. On very hot days, you’ll want to keep the plant a little bit further from the window.

2. Water

The shallow roots of ageratum plants cause them to dry out very fast if they are not water often enough. You’ll want to make a point of watering your plant once or twice each week. If your plant is outside and the weather is particularly warm, you’ll likely need to water it more often. It is best to water these plants in the morning to keep them healthy.

3. Climate

Ageratum plants can be grown in hardiness zones of 2 through 12. They tend to do best in tropical and sub-tropical climate regions, as they native to South and Central America. These plants are annuals when they are grow inside, but they are perennials in the wild.

4. Soil

You will need to grow your ageratum plant in soil that is well-drained and very rich. Make sure that the soil does not have an acidity that exceeds 7.0 pH. It is not a good idea to mix soil and sand when growing these plants.

If you are transplanting, you’ll need to maintain a distance of eight to ten inches between each plant. This will ensure that the root ball has enough space to spread out so it doesn’t get tangled. 

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It’s also a good idea to put a couple of inches of mulch around the bottom of the plant to keep it adequately moist. You can use organic compost or grass clippings. Replace the mulch whenever you notice it starting to decompose. It is imperative that it remains fresh.

Ageratum Plant Care Growing Guide

5. Temperature

A temperature range of 40 to 85 degrees Fahrenheit is best for these plants. While they can be grown in cooler areas, they do particularly well with plenty of warmth and sunlight.

6. Repotting

When you are going about repotting an ageratum plant, you’ll need to be especially careful not to damage the rootball, as it can become tangled. Put the plant into a slightly larger container with fresh rich soil that drains well.

7. Speed of Growth

These plants tend to grow fairly quickly, so you’ll need to be prepared for that. This is especially true when they are given lots of sunlight on a daily basis.

8. Height and Spread

A vast majority of ageratum plants grow to be anywhere from 6 to 24 inches tall with a spread of 6 to 18 inches. There are, however, certain cultivars that can reach up to 36 inches tall.

9. Flowers

These plants produce remarkably beautiful blue flowers that smell nice and sweet. They have a fuzzy texture and form all over the plant. You can expect your ageratum to bloom in late spring all the way up until frost starts to form.

The heads of each flower are very dense, adding a nice splash of color to the landscaping around your home. This plant can also produce flowers in other colors, including white, red, pink, burgundy, mauve, and purple.

10. Trimming

It is important that you cut off any blossoms that have browned. Make sure that you cut them off very close to the stem to minimize damage. This plant doesn’t require a ton of trimming, but it can be necessary when it starts to overgrow.

Is the Ageratum Poisonous?

This plant is toxic to both humans and animals, so it is important that you are aware of this if you have pets or small children. Ingesting any part of this plant can cause toxic reaction.  It is particularly dangerous for grazing animals, such as cows and horses.

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How to get Ageratums to Flower

The best way to encourage flowering with your ageratum is to provide it with plenty of water on a consistent basis. It is particularly important to do this before it has been established. Getting rid of dead flowers will encourage this plant to produce even more in the future.

Common Ageratum Diseases

These plants are very vulnerable to certain fungal and bacterial infections, though they can typically be treated fairly easily. Botrytis is a type of mildew that is fairly common with these plants; it forms when the soil is too wet and causes root rot.

There are a number of pests that can do a lot of damage to these plants, including aphids, fungus gnats, thrips, plant lice, whiteflies, and red spider mites.

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You’ll find that the ageratum plant is breathtakingly beautiful when it blooms. It can make for a perfect addition to just about any garden. You will, however, need to make sure that it gets enough water. These plants can dry out in a very short period of time, so you have to keep the soil moist but not too wet.

Remember that full sunlight is definitely best for these plants. They can survive in partial shade, but it is usually not recommended unless you live in a very hot region. One of the great things about these plants is they don’t require a whole lot of pruning. It is important to get rid of blossoms that brown very promptly though.

It’s also crucial to keep in mind that the ageratum plant is considered to be highly toxic. If you are going to grow it indoors, make sure your pets cannot easily get to it. You will also need to make a point of checking for pests each day so your plant continues to grow strong and healthy.

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