Once the blooms start to open, they will likely bow the spike, tho it depends how many blooms / how large they are.
I have left Sharry Baby spikes unstaked, but in the 5" pot the plant was in at the time, it was difficult to keep the plant upright - it also makes watering difficult. What I like to do for the long Sharry Baby spikes, it's to use short stakes ( 12-18"), and then when flowers start to open on the 4-4.5' spikes, they make a lovely cascade - no long curved wires required, and some spikes still hang lower than the table top
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