i saw that some people were having problems with the rank 6 garden pests. Ant Lion is only available at a higher gardening level than 10. in the meantime you can buy Itsy Bitsy Spider (gets rid of pests up to Rank 6) and Strawman (prevents Rank 6 pests for 48 hours) gardening treasure cards in the Bazaar.
The Ant Lion and Strawman trained spells aren't available until we quest well into Khrysalis, around level 90-95. Yet we can reach gardening level 10 and run into rank 6 or 7 pests long before we finish Krokotopia.
If treasure card versions of Ant Lion and Strawman aren't available, we can also train the "Summon Pixie" spell in Krokotopia. She costs an insane amount of gold to train (175,000), but can save a plant if treasure cards for ant lion or strawman aren't available. Once you've learned her, for 25 energy she will remove pests of any rank from one plant and keep all pests away from that plant for 48 hours. As an added bonus, any plants in the area will "like" her and grow 25% faster while she's there.
Summon Pixie treasure cards can sometimes be found in the bazaar as well.
Also, the Botanical Garden house has a plant NPC that drops these kinds of treasure cards as a daily reward. Even if you don't have the house yourself, you can visit one on the Castle Tours and get a reward once every 24 hours.
Alia Misthaven