Earlier forms like 
and 
show a plant with visible roots.¹ The same plant can be seen in for example 
(modern 奏) which shows the plant being offered with two hands. In ancient times plants often figured in rituals, specifically rituals where favors were being asked. One theory about how 求/ got its meaning of seek is that it was not used as a direct representation (i.e. a plant), but as a symbol for the act of the ritual in which it was used: seeking help from the gods.²
Mnemonic: Offer a plant in a request
For a long time the standard explanation for 求 has been that it is the predecessor (protoform) of 裘 “fur clothing”. In its earliest known form it would have expressed the meaning of “fur” or “fur clothing” pictographically. In this explanation at a somewhat later stage 求 was borrowed for its sound to express the meanings “to seek for, to ask for”. More or less at the same time a new graph 裘 was created to carry the original meaning of “fur clothing” through adding the signific clothing 衣 to the original 求 for clarification.
This is a common enough scenario, but in this instance it does not seem to fit, because it persuaded scholars to group together graphs that look very different. Take a look at the variant forms that Katō et al. display in their entry for 求.
| 〔契文〕 |  |  |  |
| 〔金文〕 |  |  |  |
| 〔篆文〕 |  | ||
| 〔古文〕 |  |
Katō et al. use the term 契文 keibun for 甲骨文字 kōkotsu moji (oracle bone inscriptions, short: OBI), the oldest known forms of the graphs. The first two OBI are different from the third. In the row for bronze inscriptions (金文 kinbun) the first looks like the first and the second OBI (except that a sign for hand seems to be inserted in the middle). The second and third of the bronze inscriptions look like the third OBI. Katō et al. explain these remarkable differences as alternating between “pictural representations of fur clothing” and “pictural representations of suspended fur”.¹
In the third row we see an example of a seal character. It consists of clothing 衣/
, with the seal form inserted. Xǔ Shèn 許慎 (c. 58 – c. 148 CE) analyses this graph in his famous dictionary of graphical etymology as follows:
That means that according to Xǔ Shèn the function of 求 is to add a hint for the pronunciation of 裘. Qiú Xīguī explains the entire development of 裘 from OBI to seal.
(bone)
(bronze)
(bronze)
(seal) ″裘″ qiú ″fur garment.″ The protoform of ″裘″ qiú ″fur garment″ was a pictograph; later the phonetic symbol ″又″ yòu was added. Still later the pictographic symbol that represented a fur garment was changed to the component ″衣″ yī ″clothing″ and it became an ordinary phonogram. Probably in order to accommodate a change in pronunciation, ″又″ was later changed to ″求″ qiú ″seek.″ ³
In other words, Qiú thinks also that 求 only comes along as a phonetic in building 裘. The OBI 
(a variant of clothing with strokes added to indicate fur) was the predecessor of 裘, but not of 求. Only the odd, supposedly “suspended” variants (like and, probably a depiction of a plant) are the predecessors of 求.
According to Ochiai scholars confused and in trying to identify the protoform of 求. He suggests that the reason for that can be found in a note that Xǔ Shèn added to his entry on 裘:
求，古文省衣。 As for 求, ancient writing omits 衣. ⁴
Ochiai thinks that when Xǔ Shèn stated that the ancients wrote 裘 as 求, omitting the signific 衣 of contemporary usage, this meant that 求 was used only for its sound, as a loan graph. However, other scholars may have taken this as an indication that 求 was the protoform of 裘. ⁵ All things considered, I think the viewpoints of Ochiai and Qiú are more plausible.
Looking at 求/ disentangled from instances of 裘/, we can see that both OBI and bronze inscriptions of 求 look not unlike 来/來 (a representation of wheat). Ochiai thinks that 求 is actually a variant of 来/來 that emphasizes its roots. Further, looking at how 求 is used in the earliest compound characters, like for example 奏, where 求 is being offered with two hands, and another graph (no equivalent modern form, see below) where 求 is being planted in the ground, Ochiai writes that it is valid to conclude that 求 on itself was used as a symbol for the religious act in which it was being offered and/or planted.
The graph 来/來 (depicting wheat) was simply borrowed for its sound to convey an ancient Chinese word meaning “to come”. Many scholars think 求 was also borrowed for its sound.⁶ Ochiai thinks it depicted a plant and was used as a symbol for the expression to seek help from the gods. In its modern form 求 doesn’t look a lot like a plant any more (although it does resemble possibly related 来/來 still somewhat). Henshall creates a mnemonic by comparing 求 to 水 (water) (but adds a confusing reference to fur).⁷
• For an alternative mnemonic, how about: Holy plant demands water?
• Or (exploiting the similarity of 求 vs 来/來): We come in supplication.⁸
• Finally (not depending on other graphs, but perhaps blasphemous): To seek Jesus (a cross, arms and legs left and right, head to the right, 求).
