Learn Russian: В теплице овощи гораздо более устойчивы к морозу. - In the greenhouse, vegetables are much more resistant to frost.

You cannot use очень (very) with comparatives in Russian. To say "much more" or "far more," you must use a word like гораздо or намного before the comparative. So гораздо более устойчивы correctly translates to "much more resistant."

How does the word более work with the adjective in this sentence?

Более means "more." While many common Russian adjectives have a special one-word comparative form (like быстрее for faster), longer multi-syllable adjectives often form the comparative by simply placing более in front. Here, it is paired with the short plural adjective устойчивы to mean "more resistant."

Can I use the long form устойчивые instead of the short form устойчивы here?

It is much more natural to use the short form устойчивы. When an adjective is the main state of the sentence (the predicate) and is linked to a dependent phrase like к морозу (to frost), Russian strongly prefers the short form. The long form is mostly used when the adjective sits directly next to a noun, like in устойчивые овощи (resistant vegetables).

Why do we use the preposition к and the dative case for "to frost"?