We're changing our WunderBlogs. Learn more about this important update on our FAQ page.

Buying Plants - Is Bigger Better?

By: Susan Handjian , 9:40 PM GMT on April 07, 2013

As all gardeners know, a trip to the nursery is full of enticements. Everything looks so lush and beautiful, and if a four inch pot of lavender looks nearly perfect, then a one gallon pot of the same plant must be even more desirable, right? Not necessarily. It’s perfectly understandable to think that bigger is better, but that may not always be the case with plants. There are some things to think through.

I have looked everywhere for an article from a long ago issue of Sunset that had a profound influence on my thinking about plants. It’s now tucked away in a special place (in other words, it’s most likely lost), but I remember its lesson vividly. It compared the growth of a perennial sea lavender from a six pack, a four inch pot and a one gallon pot. At the end of a full growing season, the plants from the six pack were about half the size of the four inch, and the plant from the four inch was as large as the plant from the one gallon container. The article explained that while the plant from the one gallon was larger than the four inch specimen, it was also older and therefore experienced some shock that the younger, smaller plant did not. It was ready to take off the moment it went into the ground.

This same outcome is even more pronounced when a one gallon plant is compared to a five gallon plant. The plant in the larger container could be several years old, quite content to be growing in a rich medium, while the one gallon plant will be much younger and with far less room for its roots to be comfortable. The proof is when these plants are actually put into the ground. All other things being equal, the larger and older plant may endure a prolonged period of shock and adjustment after planting, while the younger, smaller plant is ready to take off and get growing.

There are several lessons to be learned from these experiments. When there are good looking specimens of the plant you want in four inch and one gallon containers, the four inch is your best bet for quick results. It is also your best buy. At some nurseries you can buy two 4 inch pots for the price of a single one gallon pot. That’s a bargain that even instant gratification can’t compete with. As a bonus, I also find the four inch pot the easiest size to put into the ground.

Here are some sizes and types of plant containers you can most readily expect to find at the nursery, although I’ve noticed in the past few years the emergence of 1 quart and 2 gallon pots as well as some two and four inchers made of recycled materials and of coir, or coconut fiber, and peat.

Here's a general idea of what plants you'll most likely find in what containers:

Six pack: herbs, vegetables, annual bedding plants such as impatiens, and some ground covers
Two and four inch: vegetables, annuals, perennials
1 gallon: some annuals, perennials, smaller shrubs
5 gallon: some perennials, shrubs, smaller, younger trees
15 gallon: large shrubs and young trees
24”, 36” and 48” boxes: trees

Roots: The Heart of the Matter

Before you make your purchase, take a moment to discreetly peek at the rootball of the plant. Gently turn plant out of container enough for you to get a good look at the root system. You’ll see one of three things: 1) beautiful, healthy rootball with white roots reaching to the outside, just holding together the mass; 2) mostly soil, few roots, or 3) mostly reddish or brown roots and little to no soil, meaning the plant is rootbound.

If you’re fortunate enough to find the fresh, healthy rootball, off to the cashier with you. There’s nothing more to be done except take your treasure home and dig a hole.

If you discover an underdeveloped root system, the plant has probably recently been moved up to a larger pot and needs more time to develop. That plant has to go back on the shelf for a few more weeks.

The rootbound plant poses several challenges. In six packs and 4 inchers, you can be pretty rough. It’s not uncommon at all to see gardeners take a tiny plant from a six pack and pull the root system apart about halfway up, then plant. Some rootbound four inch pots will have even taken on the shape of the pot. Pull those compacted roots away and toss them in the compost pile, and then score the sides gently with a sharp, clean knife. That will stimulate new root growth and get the plants off to a faster start. See below how some rootbound six packs were liberated prior to planting. Although the treatement looks harsh, these plants now have a new lease on life.

Unless you are willing to take action to help it, a severely rootbound plant is doomed. Confined roots don’t have the capacity to absorb moisture and nutrients from the soil once planted, and even a warm day will cause such a plant to wilt and even die before it becomes established.

The rootball itself is a solid mass of roots growing around and around until it becomes girdled. Once extricated from the pot, this mass must be cut and scored with hand shears and a knife, even pulled off the bottom. Sometimes roots can even be seen growing out the top of the container.

A nurseryman whose opinion I value highly advises removing all the soil from such a plant by hosing off the root system, trimming and teasing the roots, then planting as if it were a bare root specimen. It seems quite radical at first, but I do believe his claim that a girdled root system may never allow moisture to reach the center of the underground root mass, leading to the heartbreaking death of plants during hot spells.

Full Bloom: To Buy or Not to Buy

One final thought. As enticing as blooms can be, don’t buy a plant in full bloom if there’s another specimen nearby that has only buds, or even better, lots of healthy green top growth and just a few buds beginning to develop. Allow the plant to have its first bloom in the ground, not in the pot. A plant that is blooming in a nursery container has invested tremendous energy into blooming and will have little left to develop roots. It is already stunted. Growers fertilize plants heavily and even put plants under intense lighting before sending them to market in order to bewitch the unsophisticated, but more educated and savvy customers now realize that blooming in the pot is not desirable.

Have fun at the nursery!

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

Log In or Join

You be able to leave comments on this blog.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 9 - 1

Page: 1 — Blog Index

9. WunderAlertBot (Admin)
4:48 PM GMT on April 26, 2013
gardencoach has created a new entry.
8. calpoppy
1:30 PM GMT on April 25, 2013
Good idea to give to people to look at the root ball before buying plants! It doesn't take much to take them out of the container, though I would suggest to ask first! Since I am a nursery person I would appreciate you asking me or asking me to do it for you. Sometimes on 6 pks the roots have grown together on the top so it takes a little bit of pulling to get them apart.

Also a plug for REAL nurseries, please help out independent nurseries. We need your help, the big box stores have made a lot of independents go out of business. So shop around big box and independents!

Member Since: December 31, 1969 Posts: Comments:
7. hurricanecrab
3:28 AM GMT on April 25, 2013
A nursery. What would that be like. I think I remember them fondly. :D

Excellent blog, as always GardenCoach.

I have learned that almost any plant I grow or acquire wants to be pinched back when it is small, such that it will tend toward width, rather than height.

I have learned that intial brachiations of teenage plants are almost always the strongest, as long as they are somewhat close to each other along the trunk of the plant.

Sometimes it benefits a small potted plant to be starved for water in between its growth spurts, because it sometimes promotes root growth; this [i]seems[/i] to be true (to me) particularly with fruiting trees.

Member Since: December 31, 1969 Posts: Comments:
6. palmettobug53
4:58 PM GMT on April 13, 2013
GG, I do that, too. Peruse the clearance plants at Lowe's, take them home, prune off dead and spent bits, loosen up that root ball, plant, apply lots of TLC and be patient. I'm seldom disappointed. On the occasions that they just don't 'do', I'm not out big bucks.
Member Since: December 31, 1969 Posts: Comments:
5. GardenGrrl
3:45 PM GMT on April 12, 2013
Best blog yet just in time for the impulse buy season ;-)

If it's on sale ridiculously cheap I will buy large full bloom annuals. It takes a lot of self control not to do that with perennials.

One thing I have found if one is on a budget is to go to Lowes and look for their half price "spent" perennials. Plant them. Nurture them and wait for next year. Your part about being "root bound" is real important in selecting the half price plants.
Member Since: December 31, 1969 Posts: Comments:
4. palmettobug53
4:34 PM GMT on April 08, 2013
Yep. I forgot to mention that its a good idea to pinch off the flowers once you have them planted. You are correct in that small plants (esp the 6 packs) are expending all their energy upwards to the blooms, instead of downwards to the roots.
Member Since: December 31, 1969 Posts: Comments:
3. aislinnpaps
10:42 AM GMT on April 08, 2013
Thank you for a very informative blog, gave me a lot to think about. I live about an hour from a good number of plant nurseries and went to their annual festival where they are open to the public. Last year was awesome in plant choices and I looked forward to this year. A disappointment in that there was little in bloom and less choice. After going to the fourth or fifth one I thought back over the last few months of weather, very little sun and a lot of cloudy weather and rain, and realize now they did their job right. None had tried to force blooming. Most flowers were in four and six inch pots. I had to wait a couple of weeks before I was able to plant them as I needed the dirt put into the garden, but I was able to do it this weekend. All are healthy and look great. I especially love two daisy trees I picked up.
Member Since: December 31, 1969 Posts: Comments:
2. Susan Handjian
3:21 AM GMT on April 08, 2013
You bring up some excellent points, and I agree that it's a smart idea to see a few blooms before you buy. This is especially true when there's a specific color scheme.
I was referring to the great variety of annuals and perennials available at this time of year. Many of them have been pushed to be in full bloom for instant gratification for the customer. This isn't good news, though, for the gardener who buys these plants in full bloom anticipating a season of blossoms. Those young plants loaded with flowers are using all their energy to bloom, and when they go into the ground they are unable to expend the energy to put down vigorous roots. A general rule of thumb is to remove all flowers from a plant when they go into the ground. They are able to establish themselves much more successfully if they can direct all their energy to root building.
Very interesting information about azaleas, and may be true of all flowering shrubs.

Thanks for your thoughtful comments.
Member Since: December 31, 1969 Posts: Comments:
1. palmettobug53
11:37 PM GMT on April 07, 2013
Hmmmm.... food for thought.

I've not bought many plants in gallon or larger sizes; mainly for financial reasons.

I have bought quite a number of 6 packs and 4 inch pots.

I always loosen up the root ball before planting, no matter what sized pot I've bought. It's just something I've learned from my Dad and the rest of the family.

I prefer to buy things that are blooming to be sure that I'm getting the color I want. They don't have to be in actual full bloom but you do need to see some of the flowers to be sure you're getting what you want. You can't go by the little plastic info thingy that's stuck in the pot. They often get switched by customers. Labels on the pots aren't always a sure thing, either.

It's one thing I've always heard about azaleas: don't buy one that doesn't have at least a bloom or two open. Most people are looking for certain color azaleas for their landscaping scheme and that's the only way to know for sure.

Even with the little 6 packs, if each plant doesn't have at least one bloom, I often give them a pass. I've found that if only one or two are blooming and are the color I want, sometimes the non-blooming plants in the pack turn out to be another color.

That happened to me last year, when buying 6 packs of petunias to do up some hanging baskets. I wanted white and magenta and wound up with a couple of reds. It wasn't earth shattering but I was a little disappointed.

I don't care that much, if I'm planting in beds. I'm flexible there. But a mixed container? I'm usually going for a specific color scheme and want to be sure I'm getting exactly the colors I want.
Member Since: December 31, 1969 Posts: Comments:

Viewing: 9 - 1

Page: 1 — Blog Index

Top of Page
Ad Blocker Enabled

Garden Coach's Blog for Gardeners

About gardencoach

Susan Handjian is a garden educator in the San Francisco Bay Area. She was a contributing editor of Plants and Landscapes for Summer-Dry Climates.