I would not transition outdoors until after last chance of frost. While this plant is rated safe for zones 8-10 and therefore can take some frost, I see several references to planting recommendations which states 9-10.

If you have a bulb which is exposed to mild frost (28-30F) in fall as it is going dormant, it should survive, but that is not the same as putting the bulb outdoors (and expect it to grow) when temperatures are below freezing.

I would wait to transition outdoors until night temperatures are consistently above 40F. Evenso, make sure you harden off properly.

Between 40-45F there will be no growth, and between 50-55F the growth will be minimal. Above these temperatures, growth will be stronger.

If you wait until night temperatures are warmer, you will get better results. Even if bulb is not destroyed, you do not want to put an amaryllis outdoors (which you have growing actively indoors now) only for it to go into dormancy now.

Wait another month to month and a half atleast.

By the way:
- in reference to another post: you can try to remove the bulb from the pot (or pot up to a much larger pot) when moving outdoors. This should give more leaves and heavier growth.

Ok...since I posted this, our weather here in Virginia went CRAZY!!! It got so cold again...we even had some snow. Now it's steadily warming up, highs would be in 70s and lows in 40s. My Amaryllises are basking out in the sun right now. I'll bring them back inside later this afternoon.
"Make sure you harden off properly"...ummmm...what does that mean?

hi mariava, see this link for hardening off.

Yikes...thanks for that info Tokyomafia. Bringing them back inside the house would have reversed the hardening process. I'll put them in my unheated garage tonight then.

Bumping this for the upcoming Spring weather! =)

Hardening Transplants
by Curtis E. Swift, Ph.D.
Area Extension Agent (Horticulture)

Introduction:

The transplanting process can be a shock to rapidly growing seedlings especially when set out into the cold windy garden in the spring. This is especially true for transplants started in the greenhouse, cold frame, hotbed or home. These young seedlings can be made somewhat resistant to heat, cold temperatures, drying and whipping winds, certain types of insect injury, injury from blowing sand and soil particles and low soil moisture by a process termed "hardening".

The term "hardening" refers to any treatment that results in a firming or hardening of plant tissue. Such a treatment reduces the growth rate, thickens the cuticle and waxy layers, reduces the percentage of freezable water in the plant and often results in a pink color in stems, leaf veins and petioles. Such plants often have smaller and darker green leaves than nonhardened plants. Hardening results in an increased level of carbohydrates in the plant permitting a more rapid root development than occurs in nonhardened plants.

Cool-season flower and vegetable plants can develop hardiness allowing them to withstand subfreezing temperatures. Unhardened cabbage seedlings have been reported to be damaged by temperatures of -2 degrees C (28 degrees F) while hardened cabbage will tolerate temperatures as low as -6 degrees C (22 degrees F).

Warm-season types of plants even when hardened, will not withstand temperatures much below freezing. If transplanted to the garden or field prior to the average last killing spring frost, such plants should be provided protection by hot caps or other such devices.

Method:

Any of the following can be used to harden transplants. A combination of all these techniques at one time is more effective.

1. Gradually reduce water - water lightly at less frequent intervals but do not allow the plants to wilt severely.

2. Expose plants to lower temperature than is reported as optimal for their growth. If biennials are exposed to cold for an extended period, they may bolt in lieu of developing properly. Note: Placing the plants outside during the day to encourage hardening and then bringing the plants back into the warm house during the night often reverses the hardening process. Plants could be placed in a cold frame or other area that does not freeze during the night hours without lose of the hardening process.

3. Do not fertilize, particularly with nitrogen immediately before or during the hardening process. A starter solution or liquid fertilizer could however be applied to the hardened transplants one or two days prior to transplanting into the garden or at the time of transplanting.

4. Gradually expose the plants to more sunlight. This results in the development of a thicker cuticle layer thereby reducing water loss.

Cautions:

Hardening is not necessary for all transplants. Splittstoesser recommends that with the exception of tomatoes, plants that are susceptible to frost should not be hardened. Overly hardened plants while withstanding unfavorable outside conditions are slow to get started and may never overcome the stress placed on the plant during the hardening process. Lorenz and Maynard recommend that plants be hardened for no longer than seven to ten days before planting to the garden site.

Entered by Violet_Z6

I don't plan on bringing any of my bulbs outside until the cutoff date for frost in my area, and when I do finally get them all out, they will be in partial shade until they can adequately handle more sun. I don't plan on taking any chances of losing a bulb.

I won't wait until it gets chilly in the fall to bring them in, either... they will be in before the temperatures begin to drop too much at night.

If I don't get my screen protection built my poor babies will spend the summer inside. (damned maggots! LOL) My last frost date is Memorial Day May 23 I believe. AHHHHHHHHHHHHHHHHHHHHHHHHHHHH
I want planting weather already!!!!!

Hi Chaz! Is the weather there safe enough to ship your jumbo Minerva? Email me if it is and I'll ship it asap.

Maria,

I don't know if I can explain this, but I will try.

I cannot answer for all because my climate is different than most.

This is what I do every year, and it seems to work for me.

Some, of course, are in the ground. If they have a scape and it looks like frost, I put a bucket over the scape to protect it (just in case). This does not happen every year, but does happen. Many days of warm temperatures and a sudden cold front.

I never worry about the leaves being frost bitten by one of these late cold fronts, but I know that the bloom buds can be affected by them. This doesn't happen often, but it did happen this year.

This is my usual schedule:

In the fall, I wait until the very last minute to bring most inside. Cybisters and species will be placed in a protected area before first frost, but the hybrid Tets remain outside.

This may sound horrid, but I let the first frost melt the leaves. This first frost only last a day or two (only an hour or two in the early morning hours), and then I let the leaves dry, so they are easily removed.

Then, I start bringing them inside. I have a lot of time in between first, second and third frost, so I do not worry about bringing them inside all at once. I am definitely picky about which come inside first.

Most, obviously will be dormant, and I do not water them until I see an emerging scape or bloom. In fact, I am not in a hurry to water them at this time. The exception to this will be seedlings that tend to produce leaves early, even though it is still quite cool on some nights in protected areas.

When winter is over (average last frost March 15), I watch the weather reports carefully. I take some of the bigger pots that have many bulbs outside and start hardening them off. If there is a threat of frost, I bring them inside. Frost does not harm the hybrid Tets that I have, and I have many (most are still in pots).

I do not start taking the smaller pots (1-2 gallon) outside until after the very last chance of frost. By this time, the temperatures are averaging upper 70's to lower 60's with an occasional dip below 50. That is NOW!

In my experience, 40's will not hurt a bulb that is dormant. 40's will slow down the growth of a bulb that is not dormant. In most cases, temporary lows of 40's will not damage a scape or newly formed leaves or the bulb itself. That is inclusive of cybisters because I do not always keep the protected areas heated. Keep in mind, though, that these lows do not last very many hours in my climate.

But, I have to be honest, I am very protective of my newly acquired cybisters. I simply do not have enough experience with them.

I do not know if any of that helped, but I hope it does.

Please keep in mind that I prefer to NOT force bulbs, but rather take advantage of my climate. I realize that most of you cannot do that.

I have never refrigerated bulbs, but then again, I don't see the need to do so.

I surely hope my experience helps...

It does, Elizabeth, thank you... I think a lot of us can translate some of your information to our own individual climates.

I prefer not to force my bulbs, either... but I think that in the interest of space I may have to refrigerate some of them this year.

The frost cut-off date for the Midwest, zones 4 and 5, is somewhere right around May 15th. Since I've moved south into Central Illinois, the cut-off date is a little prior to the 15th... and with global warming, that date seems to be even earlier, by almost a week.

We do have occasional late frosts or cold spells... last spring, we had a late frost that killed all the buds on the lilacs and wilted quite a few plants. I'm hoping that doesn't happen again this year... but here in Illinois, the saying goes: "If you don't like the weather, wait a minute!"

I think that regardless of how we each handle our bulbs in our respective climates, the bottom line is to protect the actual bulb from frost damage.

I envy those that can plant tender bulbs directly in the garden and not worry about frosts or winter cold... but there are trade-offs to living in tropical climates, too... tulips, lilacs, peonies, deciduous trees and shrubs, and other plants that require a cold dormancy can't be grown in the southernmost zones. So, at the end of the day, we all have our gardening crosses to bear...

I think that after learning the different methods of growing and bringing Hippeastrum bulbs into bloom, and considering our individual climates, we will all begin to fall into a pattern year by year, season by season, of how we treat our bulbs to keep them healthy and get the most out of them!