How to Plant, Grow and Care For Portulaca

When choosing plants for our backyards, we usually look for all-rounders: Plants that look great in the garden, handle various conditions, and don’t demand too much attention. One gorgeous ornamental that ticks all these boxes is Portulaca grandiflora.

Commonly known as moss rose, this succulent plant comes with a long list of benefits and uses. It is drought-tolerant, handles heat well, and produces masses of colorful flowers to light up beds and baskets. They are incredibly low-maintenance and easy to grow from seed, filling your garden with color year after year.

If you’ve fallen in love with Portulaca, this guide will cover everything you need to know about growing, planting, and caring for them.

About Portulaca

Portulaca grandiflora, or moss rose, is an adorable succulent plant from the Portulaca genus. This genus is so special it has its own family – Portulacaceae – known as purslanes. These succulent-like annuals are known for their delicate, rose-like flowers (hence the common name) and fleshy succulent foliage that pops up in needles along the stem.

The genus name Portulaca comes from the Latin portula meaning “little door,” referencing the seed capsule that holds masses of tiny seeds for spreading.

Portulaca flowers’ vibrant colors and ease of growth have made these plants must-haves for ornamental and water-wise gardens. From captivating reds to bright yellows or pops of pink and oranges, there is a variety to match every garden’s color scheme. Seed packets often come with mixed colors to create a vibrant kaleidoscope wherever they are scattered.

History & Uses

Portulaca comes from harsh and arid conditions, making it incredibly resilient and adaptable. Over the centuries, plants in this genus have been used for both ornamental and medicinal purposes to treat various ailments. However, the plant’s aesthetic appeal – particularly Portulaca grandiflora – has garnered (and continues to garner) the most attention among gardeners.

Thanks to their dense growth and colorful cascading blooms, one of the best uses for Portulaca grandiflora is in hanging baskets. Their ability to withstand dry soil and plenty of heat makes them ideal for warm climates where other plants struggle in quick-drying baskets.

In beds, they remain low and compact, not drawing too much attention but exploding with color from late spring all the way into fall. When several plants are used to line beds or pathways, they make a real statement while needing little to no attention to grow well.

Characteristics

Portulacas are renowned for their ability to withstand high temperatures and thrive in full sun. Their tough nature makes them ideal for rock gardens, containers, or even as ground cover in sunny and well-draining areas.

The thin but plump leaves retain water well, allowing the plant to easily handle periods of drought. It’s an excellent succulent for warmer climates that get a lot of sunshine or intense heat but little rain. If you want to start a water-wise or xeriscaping garden, this is one plant you need on your shopping list.

The true charm of Portulaca lies in its flowers. They bloom from late spring to early fall, providing a long-lasting burst of color. When the sun sets or on overcast days, the flowers close, opening again when the sun returns.

Planting

Portulaca can often be purchased in pots from your local nursery (in the right season), but it’s far easier to grow from seed, especially if you want the plants to adapt quickly in your garden. They don’t like to be handled and have shallow root systems that don’t respond well to transplanting, so sowing direct is the best option for most gardens.

If you’re keen to get plants into the garden as soon as possible, you can start sowing indoors around 6 to 8 weeks ahead of your region’s last frost date. However, make sure you are incredibly careful with the roots when transplanting to avoid problems with shock.

Indoor-started plants benefit from a warm, safe start, which can lead to a stunning late spring bloom. But if you’re happy to wait a little longer, you’ll likely have stronger plants when direct sowing after your last frost.

Seeds

Sow seeds in a seed tray filled with a light, well-draining seedling mix. Avoid heavy mixes, as less resistance and good drainage will help develop the strongest possible root systems early on.

If your region experiences cold snaps, use a heat mat to improve germination rates, as these plants do not appreciate the cold. The soil should remain warm at around 75F for the best possible germination.

Portulaca seeds are tiny and can be difficult to handle. Empty the seed packet into your hand and sprinkle them on top of the soil (as you would when sprinkling salt). Rather than covering with a thick layer of soil, press the seeds down gently so they are in contact with the soil.

A gentle hand is essential when watering to avoid disturbing the seeds, especially once young growth emerges. Don’t disturb early growth while the shallow root systems try to take hold.

Transplanting

Maintain lightly moist soil in the initial weeks, and don’t oversaturate the soil. Germination should occur within two weeks in the right conditions, after which they will need plenty of light to boost growth. If you’re sowing indoors, you may need the help of a grow light for this step.

Thin to one seedling per cell by removing weaker seedlings to provide the stronger seedlings room to grow. Once outdoor temperatures rise and all chances of frost have passed, they are ready to move outdoors. Acclimatize them slowly by placing the tray outdoors for gradually-increasing amounts of time over a few days before introducing them to the garden – a process known as hardening off.

When transplanting, prepare your site with sandy or gritty, well-draining soil. As a succulent known for its drought tolerance, Portulaca thrives in poor soil conditions. In fact, this might even lead to more vibrant blooms.

Dig small holes and transplant your seedlings, leaving a space of about 12 inches between each one. When planting in containers, a well-draining potting mix is vital, along with drainage holes to help remove excess moisture.

How to Grow

Portulaca is an almost effortless plant that thrives more on neglect than too much attention. As long as you can start with the right conditions and add a touch of occasional care, they will provide you with a carpet of bright flowers throughout the summer months.

Light

Portulaca loves the sun, requiring a location that receives at least six to eight hours of direct sun each day. These tough plants are at their best when it’s baking down. Pick a spot with the brightest light possible for the best blooms.

In fact, without adequate sunlight, these plants won’t bloom as profusely, and their growth will appear leggy and sparse. If it’s too dark, the flowers won’t open at all. They respond to the sunlight – so give them as much as possible.

Water

Thanks to their juicy leaves that store moisture, these succulents don’t require frequent watering. Rain is often enough to keep them happy if planted outdoors and in beds. In drier climates or when growing in pots, they will require a little more attention, but never to the level that they can be demanding.

Like most succulent plants, the most important thing to remember is that Portulaca cannot tolerate waterlogged soil or overwatering. If the shallow roots stay soaked for too long, it could lead to root rot and early death. 

Along with planting in the right soil, avoiding watering when the soil is still moist is vital. They prefer to remain on the drier side.

Soil

Regarding soil, Portulaca isn’t picky – as long as it is well-draining. Amending heavy clay soil with sand or perlite can help improve conditions if your soil does not drain well enough. If growing in containers, look for a succulent and cacti potting mix for the best results, rather than standard potting soil that may not drain well enough to keep these plants happy.

Portulaca grandiflora is fairly adaptable and can even thrive in poor, rocky soils, making them an excellent choice for those areas in your garden where other plants struggle to grow.

Temperature and Humidity

As they originate from the dry and hot regions of South America, Portulaca plants are best suited to warm temperatures. They can handle the heat well and prefer temperatures above 60F for the best possible growth. Although typically grown as annuals in various USDA Zones, they can be grown as perennials in zones 10 to 12.

Humidity is also not an issue for these tough plants. They grow best in arid conditions but can thrive even in coastal areas with relatively high humidity. Extra moisture does increase your chances of fungal disease, so it’s best to keep a closer eye on the plants if you live in a high-humidity area.

Fertilizing

Portulaca plants are not heavy feeders. In most cases, they won’t require much (if any) additional fertilizer.

If your plants are growing in poor soil, you can give them a light feeding of a balanced, slow-release fertilizer at the start of the growing season. But always follow the instructions closely. 

Too much fertilizer can lead to excessive foliage growth or even root damage, limiting your chance of flowers. Under-fertilize these plants rather than over-fertilize, and if you’re not sure when you last fertilized, avoid feeding at all.

Maintenance

One of the major benefits of growing Portulaca is the limited maintenance needed to keep them happy.

Deadheading can help encourage more flowers and keep the plant looking tidy, allowing you to focus on enjoying the beautiful flowers when they open.

At the end of the growing season, you can collect seeds from your Portulaca plants to sow next year. This is an easy and cost-effective way to continue to grow these beautiful plants year after year. Alternatively, you can leave the seeds to spread naturally around your garden year after year. 

Propagation

If you can keep plants protected from cold weather indoors or in a greenhouse, Portulaca is easy to propagate from cuttings, allowing you to expand your collection. Alternatively, you can collect seeds at the end of the season to sow again the following year.

Cuttings

Propagating Portulaca from cuttings is just as easy as with any other soft-stemmed plant. Start by choosing a healthy stem from a healthy plant. Around 4 inches long is usually sufficient. Remove leaves from the stem’s lower half, leaving only the topmost leaves.

Once you have prepared your cutting, it’s time to plant. As succulents are prone to rotting, you’ll see far more success when propagating in soil. A mixture of potting soil and sand or a succulent mix works well. Stick the cut end of the stem into the prepared soil, ensuring that the nodes where you removed the leaves are completely buried.

After planting, place the pot in a warm location with plenty of bright sunlight. You won’t need to water immediately if the soil is slightly damp when planting. Once it dries out, water sparingly to avoid overwatering, as this can lead to rot.

Your cuttings should start developing roots in a few weeks, and new growth will appear. Depending on the season and your region, you can transplant these into pots for extra protection or out into the garden.

Seed

Seed capsules will develop once the plant has flowered in summer. Wait until these capsules have dried before removing them from the plant. Be careful when removing them, as they can split open quite easily, spilling the tiny seeds onto the soil below. Store the seeds in an airtight container until you are ready to plant again the following spring.  

To plant:

1. Prepare a tray or pot with a well-draining sandy soil mix.
2. Scatter the seeds thinly on the surface.
3. Press down gently.
4. Keep the seeds moist but be careful not to overwater until they germinate.

You can also leave them to self-seed naturally rather than gathering the seeds. However, this can be risky as tiny Portulaca seeds spread quite quickly and can become tough to remove if the movement of seeds is not managed. 

Common Problems

These plants are prized for their hardy nature, but they can suffer from certain problems with the wrong environment or care. While generally trouble-free, these are a few common problems you need to keep an eye out for:

Lack of Flowers

If your Portulaca plants are not blooming as expected, the most likely culprit is inadequate sunlight. Portulaca thrives in full sun and needs around six to eight hours of direct sunlight to produce its characteristic blooms.

If your plants are in a shaded or partially shaded area, move them to a sunnier spot. Additionally, ensure that your soil drains well and the plant isn’t waterlogged, as this can also negatively impact blooming.

Lack of Color

Like the lack of flowers, a lack of color often indicates insufficient sunlight. The more sun they receive, the more colorful their blooms and leaves will be. Check your plant’s location and ensure it’s getting enough direct sunlight.

Nutrient deficiencies could also cause a lack of color. A dose of balanced slow-release fertilizer can help to enhance the color of the blooms if you are worried about nutrient availability in your garden soil. 

However, as they are used to growing in nutrient-poor soils, it’s best to conduct a soil test first to determine whether this is the cause.

Flowers Won’t Open

Portulaca plants close their leaves and flowers at night and open them again in the morning light.

But if you notice that the flowers remain closed during the day and it isn’t cloudy, this could be a sign of stress. Look out for insufficient sunlight, overwatering, or even a lack of nutrients. Check your plant’s environment and adjust to restore it to good health.

Pests

Portulaca is fairly resistant to pests but can occasionally be bothered by aphids or snails and slugs. 

Aphids can be washed off with a strong stream of water or treated with insecticidal soap. For snails and slugs, hand-picking can be effective, or use a commercial slug and snail bait or a beer trap, depending on where they are planted.

Diseases

While Portulaca plants are generally disease-free, they can be affected by fungal diseases, especially in overly moist conditions or humid climates. Root rot can also be an issue if the plant is left in waterlogged soil.

To combat these issues, ensure the plant is in well-draining soil and avoid overhead watering. If you spot signs of disease, remove the affected parts and consider using a fungicide if the issue persists.

Frequently Asked Questions

Final Thoughts

Now that you’ve learned all you need to know about growing portulaca,