How to Force Hyacinth Bulbs into Early Bloom

Forcing hyacinth bulbs to bloom early indoors is a rewarding winter project that can brighten up your home with beautiful colors and fragrances during the cold weather months. With just a little bit of effort, you can have gorgeous hyacinth blooms as early as January or February when there’s still snow on the ground outside.

In this comprehensive guide I’ll walk you through everything you need to know to successfully force hyacinth bulbs from selecting the right bulbs and pre-chilling them properly to coaxing them into bloom right on schedule. Whether you want to force hyacinths in soil or water, this guide has got you covered. Let’s get started!

An Overview of Forcing Hyacinth Bulbs

Forcing simply means tricking bulbs into blooming earlier indoors than they would naturally bloom outside. Hyacinth bulbs require a period of cold temperature exposure before they will bloom. By pre-chilling them in a refrigerator or cold room for 12-16 weeks, you can satisfy this need for winter cold and have them blooming months ahead of schedule.

The basic process goes like this:

1. Select hyacinth bulb varieties best suited to forcing. Look for early, mid, and late season bloomers to stagger blooms.

2. Plant bulbs in containers or glasses with water.

3. Keep bulbs in cold (35-48°F), dark conditions for 12-16 weeks. This cold period tricks the bulbs into thinking winter has passed.

4. After pre-chilling, move to a cool room with indirect light to allow flower stems and buds to develop.

5. Enjoy gorgeous blooms in the middle of winter!

It may seem complicated but it’s really quite simple once you understand what the bulbs need. Follow the steps below and you’ll have professional-looking results.

Selecting the Best Hyacinth Bulbs for Forcing

Not all hyacinth varieties are equally well-suited to forcing. To get the biggest, fullest blooms on schedule, look for bulbs specially bred for forcing or exhibition blooms. Some top picks include:

• Early season bloomers: Gypsy Queen, Jan Bos, Pink Pearl

• Mid season bloomers: Delft Blue, Blue Jacket

• Late season bloomers: City of Haarlem, Aiolos

Larger bulbs in the 18/19 cm size tend to give the biggest blooms but take up more space in containers. The 16/17 cm size blooms nicely too. I’d steer clear of prepared hyacinth bulbs sold for holiday forcing since they decline quickly if not forced immediately. Stick to regular bulbs and pre-chill them yourself for better results.

Mixing together early, mid, and late blooming varieties will give you a continuous sequence of blooms for months of indoor color. You can also blend together different colored bulbs of the same bloom time for dazzling displays.

Pre-Chilling Hyacinth Bulbs Properly

The key to successfully forcing hyacinths is providing at least 12-16 weeks of cold, moist conditions before trying to bring them into bloom. This cold period breaks the bulbs’ internal dormancy and readies them to sprout and flower.

Ideal Pre-Chilling Conditions:

• Temperature: 35-48°F
• Duration: 12-16 weeks
• Moisture: Soil/roots kept lightly moist
• Darkness: No light during pre-chill

You have a couple options for where to pre-chill your planted bulbs:

• Refrigerator: Place pots in ziplock bags before refrigerating. Keep bulb refrig separate from produce.

• Unheated garage, basement, or cold frame: Ensure temperatures stay in 35-48°F range. Check minimum-maximum thermometer.

• Outdoors (for zones 7-8): Bury pots in ground and mulch well before winter.

Monitor soil moisture every 2 weeks and water lightly during pre-chill as needed. Don’t let roots dry out completely. Keeping bulbs in total darkness is critical – no peeking!

Planting Hyacinths in Pots vs. Glasses

You can force prepared hyacinth bulbs either in pots of soil or suspended over water in glasses. Each method has pros and cons:

Forcing in Pots

For: Easier to manage many bulbs; less risk of tipping over once blooming

Against: Soil can dry out if not watered diligently during pre-chilling

Tips: Use 8″ bulb pans with drainage. Nestle bulbs close together. Leave 1″ space below pot rim.

Forcing in Glasses

For: Watch roots develop; unique presentation; vintage appeal

Against: Hyacinth glasses are prone to tipping once flower is heavy

Tips: Change water weekly; use glass brace to support once blooming; give extra support

I like to use shallow pots and pans for larger displays and glasses for small, elegant blooms. The choice is yours! Whichever you use, plant the bulbs close together for full flowering.

Caring for Potted Bulbs During Pre-Chilling

Potted bulbs will need a little periodic care while pre-chilling to ensure success:

• Water lightly: Check soil moisture every 2 weeks. Don’t oversaturate.

• Refill water in glasses: Add water as needed to maintain water levels.

• Monitor temperatures: Ensure temps stay 35-48°F range for entire period.

• Keep in dark: No light peeking! Open refrigerator quickly when checking bulbs.

• Label pots: Mark date planted and expected bloom time.

• Watch for growth: Check weekly for sprout development after 12 weeks.

The soil should never be bone dry but also shouldn’t stay soggy wet either. Aim for evenly moist. Refill water in glasses as it evaporates or becomes discolored. Keeping bulbs in complete darkness is vital for proper chilling.

Moving Hyacinths Out of Pre-Chill

Once your hyacinths have pre-chilled for 12-16 weeks, they’ll be ready to start waking up and growing in warmth and light. Here are some signs bulbs are ready to force into bloom:

• Tops of bulbs feel swollen or “puffy”
• Sprouts are emerging and about 2″ long
• Roots are plentiful (in glasses you can watch them grow!)

Move sprouted bulbs gradually to avoid shocking them:

Week 1: Bring to 60-65°F room with very low indirect light

Week 2: Increase light exposure slightly; rotate pots for even growth

Week 3+: Move to bright sunny window once buds show color

Avoid exposing sprouted bulbs suddenly to really warm or bright conditions. Allow them to green up slowly for best results. Once buds are swelling and starting to show color, that’s your cue to move them into a bright sunny window where they’ll bloom in about 2-4 weeks.

Troubleshooting Forced Hyacinth Blooms

If your pre-chilled hyacinth bulbs don’t seem to be thriving, here are some common issues and solutions:

Problem: Sprouts are tall, spindly, and weak

Cause: Not enough light exposure after removing from pre-chill

Solution: Very gradually increase light over 2-3 weeks

Problem: Leaves are yellowing or shriveling

Cause: Soil is too dry

Solution: Water more frequently and deeply

Problem: Buds blast (shrivel up and die) before opening

Cause: Temperatures too warm after pre-chill ended

Solution: Transition bulbs gradually to 60-65°F before moving to warmer areas

Problem: Spikes are floppy and fall over

Cause: Needs more light and warmth after pre-chill

Solution: Move to warmer room with very bright light

With proper pre-chilling and transition to growth, you should get large, colorful blooms. But don’t despair if your first attempts have some hiccups. It takes a little trial and error to get the timing and conditions just right.

After Bloom Care & Reblooming

Once your forced hyacinths finish blooming, you can remove the faded flowers either by snipping them off individually or cutting the entire spike back to the base. Leave the bulb and leaves intact.

Water the pots sparingly just until the leaves yellow and die back completely. Then discard the bulbs or compost them – forced hyacinths rarely re-bloom a second year. Or you can toss the bulbs into a corner of your garden to enjoy flowers outside next spring. Though smaller than their first blooming, some varieties may rebloom in subsequent years.

Forced bulbs never quite return to full vigor after being depleted blooming indoors. But planting them in the garden after forcing is a better end than the trash bin! Just don’t expect the same magnificent blooms you got from forcing fresh bulbs.

The Reward of Winter Hyacinth Blooms

Following the simple techniques outlined here will have your pre-chilled hyacinth bulbs bursting into glorious bloom right in the middle of dreary winter. The sweet fragrance and cheery colors are a real mood booster during cold weather months.

It does take some advance planning and diligent care while they pre-chill, but the reward of having beautiful blooms so out of season more than makes up for the effort. Once you succeed at forcing hyacinths into early bloom indoors, I guarantee you’ll want to make it an annual winter tradition!

Frequency of Entities:

how to force hyacinth bulbs: 19
hyacinth: 64
bulb: 39
bloom: 24
pre-chill: 11
forcing: 16
flower: 8
cold: 11
pot: 10
glass: 7
water: 6
pre-chilled: 4
light: 10
sprout: 5
root: 5
soil: 6
refrigerator: 3
temperature: 5
darkness: 4
moisture: 2
plant: 2
chill: 2
precooling: 1
vessel: 1
vase: 1