Mixed crocuses bring this spring lawn to life! Alison, Flickr.com
When I was a child, I used to greedily go through my dad’s bulb catalogs. They were full of fascinating color photos (some, by the way, “improved” to make the plants even more desirable, but I didn’t know that yet) and short but striking descriptions. All the bulbs, according to these publications, were easy to grow and the results were absolutely certain. Already the young gardener that I was salivated at the thought of trying them out … and I did, a few each year. While my friends spent their pocket money on candy and comics, I would save mine to buy bulbs (in the fall) and seeds (in the spring).
In one of my dad’s catalogs, there was a short article that explained how to naturalize spring bulbs in the lawn, naturalization meaning to establish a plant permanently in a seemingly natural way. Thus, the lawn would fill with flowers when the snow melted, like an alpine meadow. An alpine meadow? What a fascinating idea! So, stretching my budget to its limit, I bought 10 bulbs (corms) of woodland crocus (Crocus tommasinianus), which was, according to the text, the best crocus for naturalizing, expressly to plant in the family lawn.
According to the text, the important thing was to plant the bulbs not in a circle or a square, which would look very artificial, but irregularly, in the most natural way possible. To this end, the recommendation was to toss the bulbs into the air and plant them where they fall, which I did.
Disaster! I lost 2 of my precious bulbs in the grass (easy to do when the grass is tall, as crocus bulbs are very small). I remember being so upset! (They actually reappeared in the spring, having bloomed on the surface of the ground, without even having been planted!)
Still, tossing bulbs in the air is not a logical way to do this: even as a 10-year-old, I could see that. Imagine all the individual holes you would have to dig if you had a large quantity of bulbs to naturalize. It’s way too much work!
In spite of that first error, my crocus naturalization plan was ultimately very successful. Every year, there were more and more of them. 55 years later, there are now thousands—maybe tens of thousands!—in the lawn of the family residence where my brother still lives: they practically cover the lawn for a short but striking burst of color.
The Easy Way of Naturalizing Bulbs in a Lawn
Forget throwing bulbs into the air! Or making individual holes to plant them. Here’s how to really plant bulbs in a lawn.
Rather than making individual holes for each bulb, get out a shovel and cut out a patch of sod on three sides, then slide the shovel under the sod as if to remove it, but instead fold it back. This will give you a hole in which you can plant a large quantity of small bulbs. Don’t worry about exact planting depth: bulbs will actually plant themselves deeper if they feel the need, thanks to contractile roots.
For a “natural” effect, just scatter them irregularly. I simply pour the bulbs into the hole and move them around a bit with tip of the shovel. I don’t even bother to place them right side up, leaving them as they fall: even a bulb planted upside down will flower perfectly … and eventually right itself. You can incorporate several different bulbs in the same planting hole, for example mixing bulbs of different flowering periods to extend the season of bloom.
Now, just put the sod back into place, step on it to tamp it down, then water well. The following spring, the bulbs will grow right through the sod as if it weren’t there. (That’s why the tip of a sprouting bulb is pointed: it’s designed to punch through roots and debris.)
Interestingly, this planting technique even protects crocus bulbs from squirrels: having to dig through dense sod in search of bulbs is too much effort. They prefer to harvest them from the freshly disturbed soil of your garden beds. They really only like tulip bulbs (not usually naturalized in lawns) and crocus corms anyway. (The woodland crocus [C. tommasianius] is the one crocus they won’t eat.) As for the other small bulbs (squills, snowdrops, winter aconites, etc.), squirrels ignore them.
Do not add bone meal to the planting hole! This does attract squirrels and encourages them to put in an extra effort to dig for the bulbs.
Note that small bulbs naturalize best in well-drained soil. Some, especially crocuses, will have difficulty with lawns growing on heavy clay soil that remains soggy for days after each rain.
Care of Naturalized Bulbs
In fact, no care is required. The term “naturalize” implies that after the initial planting, you simply let the bulb take care of itself. Just plant them and walk away, letting them go through their natural cycle on their own. They know what to do and will come back year after year each spring, flower, produce leaves, and then disappear as soon as the grass begins to turn green. And most spring bulbs suited to naturalizing will multiply in the lawn over the years, some forming dense clumps, others spreading more widely.
But what about mowing? When the time comes to mow the lawn, just do it! Pay no attention to the bulbs. Most bulbs will already be dormant by then anyway and their leaves will be gone or fading fast. With the latest bloomers, the leaves may not be entirely gone when it’s time to mow the lawn for the first time, but don’t worry about it. Mowing may clip off the tip of their leaves, but it won’t harm them to any extent, as the leaves were on the verge of disappearing anyway.
But Doesn’t Naturalizing Harm the Lawn?
No, it doesn’t. There are lawns jam-packed with bulbs in the spring that just as green in the summer as neighboring lawns that never see a flower. The two types of plant (bulbs and grasses) have a completely opposite growing cycle. Bulbs start growing underground in late fall and continue through the winter, then produce flowers and leaves very early in the spring, before falling into dormancy just as the lawn grasses wake up and begin to grow. The lawn continues to grow until fall, then goes dormant … just as the bulbs wake up and produce new roots. The two coexist perfectly.
It’s interesting to note that lawns planted with naturalized bulbs almost never have problems with lawn insects (grubs, chinch bugs, sod webworms, etc.), although no one knows why. Maybe the bulbs have a repellent effect?
You can care for your lawn as you see fit: mow, fertilize, dethatch and even use lawn herbicides (as long as you don’t apply them while the bulbs are in leaf). None of the above will harm the bulbs. The one thing that will do some damage to the bulbs is aerating the lawn, but the damage is minimal. Bulbs have the ability to produce replacement bulbs when injured and will recover fairly quickly. But the benefits of lawn aeration are pretty slim anyway. I never aerate my lawn, for example, and it does just fine.
Which Bulbs Shouldn’t You Naturalize in a Lawn?
You could theoretically naturalize any hardy spring or fall flowering bulb in a lawn, but dealing with bulbs that interfere with mowing is an annoyance. That includes bulbs that bloom too late, such as grape hyacinths (Muscari spp.) or most daffodils (Narcissus spp.), because they’ll be in full bloom when the grass needs its first mowing. (True enough, grape hyacinths and daffodils look beautiful in a lawn and you could just mow around them, but that takes more effort.) On the other hand, the earliest and very smallest daffodils, such as ‘February Gold’, can naturalize very well in a lawn.
Also on the “not a good choice” list are any bulbs that produce tall plants, like most alliums and fritillarias. Again, mowing will be a problem.
As for tulips, they tick off a lot of boxes and I personally don’t think they look that good in a lawn to start with, but their main flaw is that they tend to be short-lived and you’ll want naturalized bulbs to be truly, solidly perennial.
As for fall-flowering bulbs, such as cochicums (Colchicum spp.), it’s true that they create a superb effect in a fall lawn, but they produce huge leaves in late spring which would need to be mowed around. And you’d have to mow around the flowers in the fall too. You do see them naturalized in lawns on large estates, but then, estates have “people” to do the job. I think the extra effort is a bit much for the average home gardener, but of course, you choose.
You can still naturalize bigger or later-blooming bulbs on your property, just not in a lawn that you mow frequently. You can let them grow naturally in a wooded area, for example, or a meadow where the mower never goes. That way there is no need to skirt around them with the mower and thus their foliage can mature without interference.
Which Bulbs Can You Naturalize in a Lawn?
For the average home gardener, the early-blooming spring flowers, well into dormancy by the time the lawn needs mowing, are the best bulbs for lawns. Just look for bulbs with short leaves (which rules out netted irises [Iris reticulata], by the way).
Here are some of the best:
- Crocus (Crocus spp.) hardiness zones 3–8
- Daffodil, very early types (Narcissus spp.) hardiness zones 3–8
- Glory of the snow (Chionodoxa spp., now Scilla spp.) hardiness zones 3–9
- Greek anemone (Anemone blanda) hardiness zones 4–9
- Puschkinia (Puschkinia scilloides, syn. P. libanotica) hardiness zones 3–8
- Snowdrops (Galanthus spp.) hardiness zones 3–7
- Spring fumewort (Corydalis solida) hardiness zones 4–9
- Spring snowflake (Leucojum vernum) hardiness zones 4–8
- Squill (Scilla spp.) hardiness zones 2 to 7
- Winter aconite (Eranthis hyemalis) hardiness zones 3–7