Tulips are spring-flowering bulbs that need a prolonged period of cold temperature to grow and bloom properly. In most of the United States, this cold period is provided naturally by a winter spent planted outside in the ground. However, those of you in warmer regions of the country, like us here at Menagerie Farm & Flower, likely do not get the cold temperatures tulips need to thrive. That’s where pre-cooling comes into play!
WHAT IS A PRE-COOLED TULIP BULB?
Pre-chilled or pre-cooled tulips bulbs have been given time to cool at 34-45 degrees for for 6 to 12 weeks before planting. Here at Menagerie, we take care of that step for you using our temperature and humidity controlled coolers to insure the exceptional quality, health and viability of the bulbs. The same bulbs we offer in our pre-cooled tulip collection to our customers are the varieties we cool and plant here on our farm.
WHY DO TULIP BULBS NEED TO BE PRE-COOLED?
Deep South, the desert Southwest, and most of California do not get the cold temperature they need because the outdoor ambient temperature and soil temperatures in the winter are warmer than what the tulip bulb requires for proper bud and flower development. We help Mother Nature along a bit by providing the cool environment the bulb needs for success. To reach their proper flowering development, tulips must be given time pre-cooling at (34-45 degrees) by placing in a cooler (not a freezer) for 6 to 12 weeks before planting. This pre-chilling process ensures that a tulip bulb will grow and bloom properly, giving them the best opportunity to thrive.
HOW LONG DO TULIP BULBS NEED TO BE PRE-COOLED?
The length time needed for pre-chilling varies depending on your location. In general, tulip bulbs should be pre-chilled for 6-14 weeks. The longer, the better! The good news is, you can’t over-cool bulbs. Just make sure you get them in the ground in the fall or early winter at the latest.
WHAT HAPPENS TO TULIP BULBS THAT RECEIVE INSUFFICIENT COOLING TIME?
In warm climates, bulbs that haven’t been pre-cooled tend to have stunted growth. While they may still bloom, they’ll likely have shorter stems and deformed blooms (aka blind buds), or flowers that open lower down in the leaves.
WHEN IS THE IDEAL TIME TO PLANT PRE-COOLED TULIP BULBS?
Our bulbs have received the minimum amount of chill time for successful flower development and will be shipped to you at the perfect time for planting! We recommend planting your bulbs immediately upon arriving on your doorstep in late November or early December. If you can’t get them in the ground right away, place your bulbs in a cool, dark, well-ventilated location (34-50 degrees F) for an additional few weeks. We recommend planting no later than January 1st.
I LIVE IN A COLD CLIMATE. CAN I PLANT PRE-CHILLED TULIP BULBS?
Pre-cooled tulip bulbs are ideal for growing in warmer climates, USDA zones 7b-11, but can be planted in any zone as long as your ground isn't frozen.
If your ground is frozen, you can still plant your pre-chilled bulbs in a pot with potting soil. We recommend leaving your pot on an enclosed porch if available, or leaving it outside during the day and bringing it in at nighttime.
WHEN DO PRE-COOLED TULIP BULBS BLOOM?
As the weather and soil warm up in early spring, tulip bulbs burst forth with vibrant green leaves. Each tulip variety has its own bloom time, adding a delightful touch of diversity to our gardens. Early-blooming tulips grace us with their presence in March or April, while mid-blooming tulips take the spotlight in April or May. As spring progresses, late-blooming tulips emerge in May or June to enchant us with their beauty. However, nature likes to keep us guessing, so remember that the exact timing depends on weather conditions and planting location. Keep reading to learn more about the bloom time for different tulip classifications!
WHAT ARE THE DIFFERENT CLASSIFICATIONS OF TULIPS?
Tulips, with their diverse flower shapes, heights, and bloom times, are classified into 15 distinct types. Our collection proudly offers 6 of these captivating varieties. Let's take a moment to discover the unique characteristics of each tulip type:
Single Early: Single cup-shaped flowers on short stems, bloom early in the season.
Double Early: Fully double flowers on short stems, bloom early in the season.
Triumph: Cup-shaped flowers on sturdy stems, bloom in midseason.
Darwin Hybrid: Large, bowl-shaped flowers on tall stems, bloom in mid to late season.
Single Late: Cup-shaped flowers on long stems, bloom in late season.
Lily-Flowered: Pointed petals with a flared base, slightly recurved, on long stems, bloom in late season.
Fringed: Fringed or serrated petal edges, on sturdy stems, bloom in late season.
Viridiflora: Green markings on the petals, on sturdy stems, bloom in mid to late season.
Rembrandt: Broken or striped petals, on sturdy stems, bloom in mid to late season.
Parrot: Ruffled petals with irregular edges, on long stems, bloom in late season.
Double Late: Fully double flowers on long stems, bloom in late season.
Kaufmanniana: Delicate flowers with pointed petals, on short stems, bloom early in the season.
Fosteriana: Large flowers on sturdy stems, bloom early in the season.
Greigii: Wide leaves with striped or mottled patterns, on sturdy stems, bloom in midseason.
Species: Wild tulips, often smaller and more delicate than cultivated varieties.
WILL PRE-COOLED BULBS BLOOM AGAIN NEXT YEAR?
We hate to be the bearer of bad news but, generally, no. They will likely not stick around for a second season because they require their “chill” time for proper bud development, making it difficult to perennialize tulips in warmer regions. We recommend harvesting the tulips, bulb and all, for use as cut flowers in your home or enjoy the show in your garden and remove the bulbs at the end of of the season after you have enjoyed the blooms. Plan to plant another round of pre-cooled bulbs again next fall!
We hope this post helps to bring some clarity to the term “pre-cooled.” In warm climates, pre-cooling will help your tulip bulbs perform their best and bring you beautiful blooms to harvest and enjoy come springtime!
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