Miscellaneous

Perennials To Avoid – What Are Some Perennials You Shouldn’t Plant

Perennials To Avoid – What Are Some Perennials You Shouldn’t Plant


By: Mary Ellen Ellis

Most gardeners have a plant, or two, or three that theystruggled with over the years. This likely includes some unruly perennialplants that were simply a mistake to put in the garden. Perennialsare generally easy plants that come back each year, but some will cause you aheadache. Learn from the mistakes of others, and avoid these difficult plants.

How Can There Be Perennials to Avoid?

For a gardener and plant lover, it can be hard to face thefact that there are some plants you just need to avoid. In some cases, it’sbecause they aren’t suited to your particular location. For instance, you’llget nothing but trouble trying to growa succulent in your waterlogged raingarden.

On the other hand, there are perennials that are just hardfor anyone to love, no matter the local environment and conditions. Some takeover and grow out of control, requiring constant pruning or they look unrulyand messy. Others are toxic and dangerous, or they’re invasive and risk rootingout native plants in the area.

Perennials You Shouldn’t Plant

Before you put any perennials in your yard or beds, do yourresearch to avoid issues. There are plenty of perennials you’ll regret, so knowwhat you’re getting into first. Here are just some examples of perennials toavoid and the reasons why:

  • Aloe vera – Aloe is a great plant if you have no pets. The succulent leaves are attractive to dogs that like to chew, but they’re toxic.
  • Belladonna – Belladonna, also known as deadly nightshade, is pretty but deadly. It should never be a part of a garden with pets or kids.
  • Mint – Who doesn’t love herbs? Mint is so easy to grow and comes in numerous varieties. But it will be the bane of your existence as it overruns everything else you grow. Keep this herb safely contained to pots.
  • Mimosa and Japanese barberry – Both mimosa and barberries are nice plants, but they are also invasive. If you care about your native plants and the local environment, avoid them. They’ll spread, not just in your yard, but thanks to seeds and birds, into natural landscapes nearby. Barberry also harbors ticks that carry Lyme disease.
  • Water hyancinth – Another invasive perennial, this aquatic plant is popular as a water feature filter, but water hyacinth will choke out other plants and even fish.
  • Amaranthus – This stunning perennial is a nightmare for allergy sufferers. Amaranth produces a lot of pollen, so beware.
  • Yucca – This is an example of a plant that requires more effort than it’s worth. To keep yucca looking tidy, you’ll be constantly removing dead leaves. And if you want to get rid of it, expect to dig deep.
  • Lily-of-the-valley – While they’re pretty to look at and smell lovely, you might want to think twice before planting lily-of-the-valley flowers in your garden. The plant is prone to spreading quickly and getting out of hand. Control of this plant isn’t easy either. Additionally, lily-of-the-valley plants are toxic and not suitable around kids or pets.

Not all perennials are bad everywhere, so make sure you knowyour area. If in doubt about whether a plant is perennial or how it will do inyour environment, check with your localextension office.

This article was last updated on


7 Tasks to Complete for Your Winter Gardening Checklist

It won’t take long to get through all the tasks on this gardening checklist, and you’ll be glad you did once your spring garden emerges extra beautiful and green! A good, thorough garden prep is like the difference between making a meal in a clean pot or one that’s filled with leftover remnants of meals past it’s cleaner, healthier, and it looks a whole lot nicer!

Fresh mulch can actually look quite beautiful, especially if it’s a naturally-tinted bark that complements your garden’s color scheme.

Go through this gardening checklist now for a 2021 landscape design that’s on-point all year long:

1. Prune Deciduous Trees and Summer Flowering Shrubs

In winter, many landscape plants go dormant, and this is the best time to prune them. Deciduous trees, especially flowering or fruit-bearing trees, can benefit from some pruning to remove dead or diseased material, crossed branches, or even just to thin out the foliage and maintain a more manageable size.

You can also prune your summer flowering shrubs, but leave your spring-flowering shrubs alone! Spring bloomers typically produce flowers on last year’s wood, so if you prune them now, you’ll lose all your flower buds. Summer bloomers, however, grow new wood in the spring and then produce their buds, so if you prune them in winter, you won’t lose out on those flowers.

2. Test and Amend Your Soil

After last year’s gardening season, your soil is probably depleted of a lot of its nutrients, like phosphorus, potassium, or nitrogen, and the pH might also need to be adjusted as well. Performing a soil test will give you an idea of how your soil is doing and what it needs to provide the right nutrition for your plants. Pick up a simple soil test kit from our garden center in Houston , and we can offer some tips on what you can add to your soil if it needs a boost.

3. Mix In Some Compost

Compost is one of the easiest ways to bulk up your soil with organic, nutrient-dense material, not just to feed your plants but to improve moisture retention and drainage. Our soil can get pretty sandy here, and while ultra-fast drainage can prevent root rot, it’s not so great when our hot desert sun is roasting our plants. Good moisture retention is crucial for avoiding dehydration, and compost will help with that quite a bit! It also can gradually make the pH of your soil more acidic if your soil test shows that it’s a little too alkaline.

4. Replace Your Mulch

A layer of mulch further helps retain moisture in the soil for your plants while also shielding the sun from reaching weed seeds, which prevents them from germinating. Biodegradable mulches like shredded bark, straw, or mulched leaves will break down over time and release nutrients into the soil, but after a while, you’ll want to replace it so that it doesn’t become an unsightly, rotted mess. Fresh mulch can actually look quite beautiful, especially if it’s a naturally-tinted bark that complements your garden’s color scheme.

5. Clean Up Debris

Remove any old remnants of last season’s plants from the garden, as well as dropped branches, dead leaves, or any other junk that might have rolled in over the fall or winter. These materials can harbor nasty bacteria and fungi, and larger debris can create the ideal hideout for a number of unwanted garden pests that can harm our plants and landscape. Any natural materials you find that aren’t chemically treated and show no signs of disease or fungi can be tossed in the compost bin!

6. Divide Overgrown Perennials

If any of your perennial flowers or shrubs are getting a bit unruly, you can dig them up, divide them at the root ball to create two separate plants, and then replant them! Be very gentle when handling the roots, as too much root interference can really stress out the plant. You can also divide your plants that grow from rhizomes and tubers —just be sure to throw out any of the rhizomes that look diseased and only replant the healthy pieces.

While you can sometimes divide root balls by hand, sometimes it’s easier to use a sharp knife to make a clean slice through. Be sure to sanitize the knife with isopropyl alcohol before making your cut—this is like plant surgery, and you don’t want to use dirty tools, or else you could introduce harmful pathogens!

7. Start Planting your 2021 Garden!

Once your soil is prepped and ready, you can start planting! However, not all plants are suited to cool temperatures, so make sure you’re planting your cool-season plants and other cold-tolerant varieties—not the heat-loving annuals or plants that thrive off our scorching summer sun!

What Can I Plant Now in Houston?

Our mild winter temperatures allow us to plant all sorts of cool stuff to kick off the year! Whether you want some annuals for a burst of quick color, some permanent landscape plants, or some fresh vegetables to harvest in spring, you’ve got more options in front of you than the Cheesecake Factory menu.

  • Transplant Vegetable Starters like cauliflower, broccoli, lettuce greens, cabbage, and even fruits like strawberries.
  • Plant Vegetable Seeds for spinach, lettuce greens, beets, peas, radishes, and carrots. You can also start seeding your tomatoes , peppers, and eggplants indoors.
  • Cool Season Flowers like pansies, violas, dianthus, snapdragons, foxgloves, hollyhocks, poppies, and delphiniums are hardy enough to handle our winters.
  • Cool Weather Herbs like dill, cilantro, thyme, rosemary, calendula, and chervil are perfect for this time of year because they’re less likely to bolt in the heat.
  • Spring Flowering Trees and Shrubs like redbuds, spirea, azaleas, fringe trees, fruit trees, and Mexican plums are good to go in the ground now, while the soil isn’t hot from the sun.
  • Berry Bushes like blueberries and blackberries make excellent landscape plants.
  • Rose Bushes always bring the drama and the romance, so if you want to give your landscape a lavish look for 2021, now is the time to add some roses !

Ready to embark on your latest gardening adventure? We’re stocked up with everything you’ll need in your tool belt for 2021. Visit Plants for All Seasons soon so you can have your pick of the best new seeds and starter plants for a spectacular spring that’s bursting with color and life!


43 Perennials to Cut Back in the Spring

Gardeners in warm climates can treat fall, and sometimes even winter, as supplemental growing seasons. But for gardeners who experience hard winters, fall is a great time to get a head start on garden clean-up. We hear a lot about four seasons of interest in the garden, but this rarely applies to perennial plants. Most perennials turn ugly as the temperatures drop. It's nice to get your garden in order in the fall and any plant that is diseased, infested, or otherwise in poor condition should certainly be cut back and disposed of rather than leaving them to over-winter.

However, there are perennials that simply don’t fare well if they are pruned too late in the season. They need the winter protection provided by their fallen leaves to help them survive. The following list is a selection of 43 plants that are best pruned in spring.

Gardening Tip

When plants have clear symptoms of bacterial or fungal disease, it's best to prune away and dispose of the affected foliage, even if the plant normally benefits from being allowed to stand through the winter. You don't want diseased plants to remain over winter, since the microbes can spread and infect other plants. This also goes for diseased leaves and other debris covering the ground. Remove this material and apply a clean, sterile mulch for those plants that benefit from winter protection.